Safety first, or respect of your peers? Not obvious respect, but they subconsciously respect you.
Me, I don't wear a helmet and I ride to school nearly every day, I've had a few spills but no injuries whatsoever, but then again, I always ride with at least a small bit of awareness and common sense.
So what about you guys/girls?

I'm like you, I rely on my awareness of my surroundings which is actually a bit elevated since I started riding a fixed gear. I can't stop as quickly because I don't like to use my brake (even though I still have one for emergencies) so I am always looking for obstructions and paths in case I need one. I also am always watching at least a few blocks ahead of me and anticipating the actions of cars and other bikers.

That said, I don't deny that wearing a helmet would be a good move. And I do wear one when I'm in a race...I just don't deal with it on my everyday commute.

I haven't ridden(?) my bike in quite a while (mostly because winter has been bloody cold over here so summoning the will to go out is a lengthy process). If you're going to be going somewhere rough or doing tricks or jumps, by all means wear a helmet (you'd be stupid not to in those circumstances) but just casually riding around doesn't strike me as hazardous enough to warrant safety gear.

Now that I'm an old man I do, but when I was a cocky teenager I sure as hell didn't.

When riding my bicycle or skateboard, no.
When riding my motorcycle, however, I always do.

I'm from the Netherlands, absolutely nobody wears a helmet here (except maybe the 4 year olds who are just learning.) So no.

Depends on the distance, the velocity and whether or not I have somewhere to place the helmet where I'm going.

Nope. It would ruin my hair...

I ride with common sense (mostly), so I feel I don't need it. I won't probably feel that if I crash, though.

I rode by a guy who was mowing his lawn. Rock flew from the mower and damaged my helmet. I'd hate to think what would have happened if it hit me in the head or even my face instead of my helmet.

You can be as aware as you want,
but you can't predict a rock.

Dechef:
I'm from the Netherlands, absolutely nobody wears a helmet here (except maybe the 4 year olds who are just learning.) So no.

I'm from Holland too, and no, nobody wears a helmet here. Why'd anybody consider a helmet necessary? It's not like my skull is made of glass, it can take a punch. Seriously, I speak from personal experience. And on top of that, the times I hit my head never had anything to do with bikes. when falling with my bike, I usually find more than enough time to protect my head with my arms. Even while giving a demonstration of Eyetoy. Which was perhaps the reason that I fell...
Anyway, helmet while riding a bike (or ice-skating, which they recently came up with): Utter nonsense. (I would say bollocks in a hat, but then I would probably get a 'Yahtzee fanboy' label stapled to my nipple...)

I always have worn my helemt. If anyone thinks I give a fuck about their opinion of me, they can jump off the nearest bridge, preferably without water beneath it.

Not only that, but I just recovered from a serious accident were I went over the handlebars so far, it coulda shamed Niko Bellic. Broke a leg and smacked my head, which thankfully didn't hurt or damage anything thanks to my helmet and the shock.

It wasn't my fault, in my opinion. I was biking along and then some guy whipped his car door open as I was biking between a lane of parked cars and moving ones with only a meter between them.

Also, even an adult has to wear a helmet or face the wrath of the law in Canada. I don't feel like losing $500 for risking injury and trying to look slightly more badass. I can't count the amount of squad cars I see in a 10-minute commute. One is even posted in my school parking lot.

Down here wearing a helmet gets you respect, not wearing one just makes you look like you love your hair too much. However, I still don't wear one, because it's too much hassle carrying it around all the time, and if I do fall off my bike, there's a million other ways to get killed than a direct head injury crushing my skull. The point is, the helmet is not gonna save your life if you do fall.

On a bicycle no. But, on my motorcycle, absolutely. I wouldn't go without one.

I never learned how to ride a bicycle.

Absolutely! I like not being injured more than I like being injured. I mainly use my bike in the city and to commute to work, a 10 mile ride on busy city streets...

Draculafreak:
I like to wear a helmet on my HEAD, not my bike.

Touche good sir.

It doesn't quite fit on the gas mask-head.

Combined:
It doesn't quite fit on the gas mask-head.

Ah, what you've done there is get yourself mixed up with your avatar, silly Combined!

MaxMees:

Combined:
It doesn't quite fit on the gas mask-head.

Ah, what you've done there is get yourself mixed up with your avatar, silly Combined!

That's not an avatar. That's a photo.

(In all seriousness, no, I don't wear a helmet, because the ones they sell here are too small and uncomfortable.)

On motor bike? I do
On push bike? no way
I dont live in a very busy area and there are plenty of cycle tracks

no helmet for me but im only on a bike if I had a Motorbike I would wear a helmet.

Combined:

MaxMees:

Combined:
It doesn't quite fit on the gas mask-head.

Ah, what you've done there is get yourself mixed up with your avatar, silly Combined!

That's not an avatar. That's a photo.

(In all seriousness, no, I don't wear a helmet, because the ones they sell here are too small and uncomfortable.)

Mine is me too, but I don't go around in a tweed fedora doing high kicks, but then again you probably don't go everywhere turning you're head in a fixed pattern. Still you'd look awesome with a mask like that.

Heh, well my Dad's had three bad accidents leading to concussions from riding his bike around my area. That hasn't stopped me though (and I'm pretty sure he was wearing a helmet on each of those occasions anyway, lol) - helmets are just too bulky and awkward, particularly lugging into lectures n all that. I guess I could leave it locked to the bike, but it all seems like just too much hassle for a 10 min ride to and from campus everyday.

I saw an article in a mag with the Guardian a few months back where someone had gone out and measured with a range finder how far on average cars passed when he was wearing a helmet and when he wasn't, and found that when you're not wearing a helmet cars give you a wider berth, possibly indicating that drivers are more careful since you look less 'professional' or secure with no helmet, and therefore more likely to be more erratic.

How much of that is subconscious or concious, or how consistent or scientific his results were I do not know, and at the end of the day it only takes one prat looking the wrong way to mess your day up, but it made me feel better about not wearing a helmet.

EDIT: if I remember correctly, bicycle helmets are only rated for collisions under 12 mph, so if you're going down hill or get clipped by oncoming then kiss your helmet goodbye.

And I do wear a helmet mountain biking, just because I'm so much more likely to fall on rough terrain with little chance to check my fall. But still, I probably wouldn't use my head to break the fall - that's what my arms are for :D

motorcycle yes i do
bike no, although i have in the past and almost got in a few serious accidents cause it impaired my vision and had to crane my neck in an odd way

No way, Jose. But I don't even ride my bike. I'm more of a walkin' feller.

I don't care about what people think of me, but on a hot summer day I don't want my head to get all sweaty. I feel off my bike last summer and I broke my wrist, but I don't think wearing a helmet would have helped me there anyway.

You'll be hard pressed to find anyone wearing a bike helmet in the Netherlands (for the regular commute anyway). I'm guessing that because there are so many cyclists that drivers take care to pay attention and then there are all the dedicated cycle lanes.

You might stumble across a young child wearing a helmet though, maybe.

No, if i get hit by a car, I don't want to be concious until the ambulance arrives.

I walk.

Even if I rode my bike, I would not (well, while my friends saw me)

I ride every day, I own five bikes.
A Normal helmet on my mountain bikes/commute bike.
A Pisspot helmet on my Bmx
A Fullface on my Freeride bike.

If I go somewhere on a bike I'm wearing a helmet.

I meet plenty of people with 'good awareness of their sorroundings', every so often I scrape one up off the pavement with a head injury. You people are my pet peeve.

To anyone who says helmets are no good in an accident, I direct you to these photos.
http://pics.livejournal.com/fix_the_spade/pic/0000eyec
http://pics.livejournal.com/fix_the_spade/pic/0000dx6g

Clipped by a car travelling at 'some' miles an hour, ripped up the skin on my arms, shoulders and hips quite thouroughly but my head didn't take a scratch, despite being first impact on ground. As you can see the helmet was trashed.

#Edit, in case anyone uses the "but helmets are only rated to survive 12mph impacts" again, that's how cycle helmets are designed. They are designed to take a massive impact, but only take it once, once they've had a big smack they're trash. But then you're head will take a massive impact too, once.

Yes, always. I love my head. And if I lost respect with my peers,well...Fuck 'em.