How to connect to Android with ADB over TCP?

According to a post on xda-developers, you can enable ADB over WiFi from the device with the commands

setprop service.adb.tcp.port 5555
stop adbd
start adbd

And you can disable it and return ADB to listening on USB with

setprop service.adb.tcp.port -1
stop adbd
start adbd

If you have USB access already, it is even easier to switch to using WiFi. From a command line on the computer that has the device connected via USB, issue the commands

adb tcpip 5555
adb connect 192.168.0.101:5555

To tell the ADB daemon return to listening over USB

adb usb

There are also several apps on the Android Market that automate this process.