I just had an awesome idea - a program that connects to the Wii remote over Bluetooth and uses the infrared camera to detect whether or not someone walks by. Basically, you would place an LED and the Wii remote as far apart from each other as you want and aim the remote at the LED. The program keeps tabs on the infrared camera so that the second the Wii remote can no longer see the LED the program will do what the user wants -- sound an alarm, add 1 to the number of people who it has seen walk past the LED, or even snap a photo using a webcam. The only drawback to using the Wii remote in this manner is that the remote does shut off after a moment of inactivity.