If anyone has an Intel Mac and a Nintendo Wii you can use the two of them together to make a poor mans AppleTV.
Ive just set this up and it works pretty well. Music playing via iTunes is fine, but video is a touch laggy. It is still watchable, but I have a really old wireless access point, (almost 5 yrs old now) which is just a wireless bridge, that is probably the cause of the lag. Slideshows via iPhoto is pretty good too.
Its not AppleTV but if you cant plunk down the $250 for an AppleTV this works too.