Winterface isn't bad. Has a lot of issues. I'm currently playing around with an HTC Cube mod, but it kind of stinks. Honestly, the best GUI that I've used on my tilt was IFonz. DO NOT buy one of the IPhone programs that advertise. They're terrible. Mobile Shell has a lot of cool little interfaces, but if you are considering Skybox, RECONSIDER! It's not bad, but it's a huge pain in the butt to get off the phone.