Orbot offers anonymous browsing on Android, via Tor
Now The Tor Project itself has released an official Android client called Orbot, which should bring anonymous mobile browsing further into the mainstream. It's not available in the Android Market just yet, but you can already download Orbot and set it up on your Android device.
Orbot's setup is a little bit complicated. If you're on Android 1.x, the ProxySurf browser from the Android Market is compatible with Tor. On 2.x, you're going to have to take some extra steps, including rooting your phone. This is all outlined on Tor's website.
Right now, setting up Tor for Android is just a little bit too annoying to appeal to anyone but serious privacy junkies. This is a good step toward creating anonymous browsing for everyone, though.