Filled with fun new features, iChat turns any mere video chat into an event. Video backdrops, Photo Booth effects, photo slideshows, Keynote presentations, or an entire Mac desktop — you can share [...]

Filled with fun new features, iChat turns any mere video chat into an event. Video backdrops, Photo Booth effects, photo slideshows, Keynote presentations, or an entire Mac desktop — you can share it all with iChat in Mac OS X Leopard.
Movie backdrop
Chat from anywhere (or just look like it)

Set the scene for a chat with video backdrops in iChat. Drag and drop a picture or video from iPhoto, iMovie, or the Finder into the video preview window to create a backdrop that will fool your buddies into thinking you’re chatting from your living room, the beach, or the moon. Even buddies who don’t have Leopard will see your backdrop.

http://www.apple.com/macosx/leopard/ichat.html