Thought I'd chime in on this thread. I've gone through just about every kind of helmet mirror that I can find. Some I've lost because they fell off, or they have broken. The best one yet that I have used and am using now is this one:http://www.kijkom.nl/docs/reflex-e.htm. It is so super adjustable that you can adjust it so that you almost don't have to turn your head to get the rear-view that you want. It is removeable for pictures. I guess what I like best about it, though, is the fact that it is so adjustable. With the others, I was constantly turning my head, or adjusting it, to get a good view of whats coming up behind me. This mirror has a bendable arm that really helps in its mobility and functioin.

Clare
p.s. I didn't buy it from this site. My LBS ordered it for me, and I think it cost me about fifteen dollars.