There are Viper Geckos, but they need heat. Lots of heat.
http://www.ball-pythons.net/Sections...44-page-1.html

This page has a good summary of the Uroplatus geckos.
http://www.gherp.com/gherp/pages/uroplatus.htm

I think the little Uroplatus would be cool, mainly because they're so special looking.

--Maarken