Web 2.0 start ups all seem to have one thing in common design-wise. They all use non-pressable buttons. These are images that you can click to death but never push in. There are a few places that you can still pick up HTML buttons or other custom buttons that do react to being pushed, but the services that I use seem to be dominated by this button flatness.

(Clockwise from bottom: cocomment, riya, mabber, ma.gnolia, ma.gnolia).