I've been wearing helmet ever since I started riding a two-wheeler (first was Kinetic Honda, followed by Splendor, Yamaha RXG135, Bajaj Wind, Bullet Machismo and finally Avenger 200).
Every time I open Bike, I see some pictures of helmetless riders being chastised for ignoring their safety. Valid. Quite some time back, when I used to own a Yamaha RXG135, I met with an accident and I can vouch that had I not worn my helmet, my skull would've cracked. Even with the helmet on, I suffered a rather dangerous cut on my eye-lid and I bled profusely - to the extent that my friend's mother refused to recognize me when I reached his house close by, right after the mishap. Even my parents didn't recognize me what with my head and one eye bandaged in full white (a la Anil Kapoor in Meri Jung :D). I was saved nonetheless.
Having said that, times have changed for me. Then I was in Ahmedabad, now am in Mumbai. Commute 45kms every day to office and back. And every day cover my face and head with bandanas beneath the helmet to save me from dust and pollution. Helmet's necessary to say the least.
Yesterday, I rode my Avenger without a helmet. Of course, the distance was short and I was in no rush. Also I didn't have to fear any traffic policemen in our area. Wind blew ever so gently in my face and for once I - used to all sorts of covering every day for about 3 hours of riding - felt exhilarating. Hair got disheveled and I loved it. Safety didn't matter; of course, purists would say, you never know when someone can knock you down no matter how careful you are. I did it deliberately, out of convenience, out of a little desire for change. Spare me.
Riding slowly on a sunny morning on an open road is an aesthetic issue. So if you are a 'safety-first' person and never forget to helmetize your head, just do this once - go helmetless. You'll love it. And you'll love the purists frown :).