The goal of the RCDroid project is to take a remote control car and be able to connect to it with an Android device over WiFi. Our current project website can be seen here.
In a nutshell, we assembled a remote control car from a kit and wired it to be controlled by an Arduino Uno board. The board connected to a wireless router using a WiFly shield. An Android device running the appropriate app would then connect to the device and send control signals. The user utilizes the device's accelerometer for control.
Future work would include improved network capability, additional sensors (such as a camera) on the car, and a better app.