I really like the "Take-a-Look" sunglasses mirror. It's super light-weight and very adjustable. Rarely shifts at all on the bike (only when you take off your glasses and put them down). The only downside is if you stop somewhere and forget you have it on. I've gotten some pretty funny looks at the farmer's market in my sunglasses (helmet now off, hanging on my bike handlebars), with my rear-view mirror!
Emily
Emily
2011 Jamis Dakar XC "Toto" - Selle Italia Ldy Gel Flow
2007 Trek Pilot 5.0 WSD "Gloria" - Selle Italia Diva Gel Flow
2004 Bike Friday Petite Pocket Crusoe - Selle Italia Diva Gel Flow