I bought this for my TP2 and it worked great. I am now using it for my Evo and it fits even better than my TP2. You still have access to the volume buttons and the camera is not covered either. There is foam on the bottom, back, and sides so your phone is well protected from any kind of scratching at all. It works with your phone naked, or with a silicone case, and others I imagine those are just the only two that I have tried. It is pretty solid when mounted and can swivel to landscape with ease. You simply set the phone in place and then squeeze the sides together and it locks the phone(squeezing it with foam). Small button on the bottom left(seen in pic) releases the lock so the phone can be removed. Here is a link, it may not be designed for the Evo, but it fits like it was....I am super happy with it, while I think others would be too I cant gaurantee it...
http://cgi.ebay.com/ADJUSTABLE-CAR-M...item19b650f9b1