iTunes is for iPods, why can LimeWire be for MP3 players?

iTunes can download - LimeWire can download
iTunes can play music - LimeWire can play music
iTunes has a library - LimeWire has a library
iTunes has play lists - LimeWire has a play list

iTunes can upload to iPods - LimeWire can't upload to anything


I just opened "Windows Media Player" (I don't usually use it) I think I kind of like it... But... I just think that it would be a nice feature, it would be faster than having to open a second program to move files to your MP3 player.