album cover in mp3 file?

i wanted to know how to put an album cover in a mp3 file ?
example:
when i play a song in winamp, its album cover is displayed:

Answer #1
For putting album covers, what i do is download the album, put it in a folder then download the cover, rename it to ‘folder.jpg’ (not the actual foldername but just folder.jpg)and put it in the same folder. This way, Windows Media Player 9 recognises the cover and places it before the album.
For example, I have a folder named Kanye West-Graduation in which i have all the album songs. Now, in that particular folder, i put the album cover photo as foder.jpg
Answer #2
i use Tag&Rename for that, it does it pretty well, but then i stopped since it make the songs bigger.
Select your song -> right-click -> Edit Tag in selected file -> tick the “Art” checkbox on the right side and browse/add your album cover.