In reply to watson.b: I love my Petzl Meteor, I think people really underestimate the benefit of having a super light helmet. Moved up from a mates borrowed Ellios and then my own BD half dome.
I've worn it for trad and in the alps, and I really appreciate the lightness. It doesn't feel like you have anything on, super quick to adjust, all the straps fold into the body so that you get a nice easy shape to pack, and it's really comfy. Also comes with a replacement foam insert and a storage bag.
I realise they are more expensive and less durable due to being polystyrene not hard plastic, but you wont right them off with a small bump, and any sort of impact which would make me consider getting a new one would probably cast doubts on a solid plastic helmet too.
Bright orange is sexy too.