According to a study that was released by comScore that average U.S. computer has 880 MP3s (3 GB) and 36 Windows Media files (329 MB). So on average 3GB of a HD are being taken up by MP3s. I guess most people don't need 30 GB ipods.

Users with the largest MP3 collections are more likely to spend time online gambling, gaming, shopping, chatting, and doing just about any other kind of online leisure activity that was tracked

If you're reading this my bet is that you have over 3GB of music on your HD. How much hard drive space are those MP3s taking up on your computer?
[Study: you probably have 880 MP3s and 100 PDF files on your PC]