For Android 2.x devices:
You must root your device and update the firmware to an iptables-capable ROM for Orbot to transparently proxy all TCP traffic. For non-modified and non-rooted phones, you'll want to manually configure HTTP or SOCKS proxy settings for specific applications. If you root your device and install an iptables-capable ROM (such as Cyanogen), Orbot can transparently proxy traffic on an app-by-app basis through Tor. You can also install Firefox for Android from the market with the Proxy Mobile Add-on or install the text-only “NDBrowser” from the Android Market. Both of these solutions all routing of web access through Tor on standard, un-rooted devices.