If you have a strange gut feeling that your boyfriend or girlfriend is cheating on you, but you can't just find any proof, then maybe this little trick using Quartz Composer will be of some assistance. It only works if you have Tiger and an iSight or another webcam.

Quartz Composer is a development tool provided with Mac OS X v10.4 for processing and rendering graphical data. There are only two components to this trick - the video input and the billboard to render it. Now what you do is drag a line from the video's input "Image" on to the Billboard's "Image" input. After that, use the inspector to set the width to two.Export this to a QuickTime movie, 320x240. Since only one application can use your camera at a time, you'll have to close Quartz Composer for QuickTime to play the video. When you like what you have done, just embed it in HTML. I'm sure he/she will make a confession in no time.