This is a very general question, so I'll give a general answer. Besides the computer (duh) and the downloaded movie, you'll need some good software. MPEG or MPG movies can be played with Quicktime, Windows Media Player, and many, many others. AVIs can be played on Windows Media Player and on a limited level, Quicktime as well. Many AVIs you find will be encoded with the DiVX codec, which you will have to download seperately. This usually only works on a PC, but you can get a Quicktime patch from an underground website. SWF and RM files are played with Real Media Player and MOV files are played with Quicktime. There are many video files that are ASF, but I am not sure which software is good for them. :-) Can anyone out there help this guy out regarding ASF files?