I have this one attached to my drops right below the brake hood. Great mirror. It's very practical and durable.
I like the wide angle as it widens the view but some reviews online say that they can't tell the accurate distance.
For me, not a problem, esp. once you get used to it, it's pretty easy to tell where about the car behind is..

http://www.rivbike.com/products/show...-mirror/20-177
http://www.adventurecycling.org/stor...ike-mirror.cfm