Been reading someone else's blog which mentioned choosing a helmet.
Have to say, ever since I got my specialized mountain enduro pro(or something like that), I've never looked back. It gave so much ventilation and was so light, I kept forgetting it was on(thus dispelling my previous reasons for not always wearing a helmet - too hot and too heavy).
Just been thinking, when I got my ride out, all I could think of is how much I miss being out on a good trail away from cars and technology and stress.