i used this a while ago, very time consumeing.
As it says, its semi automatic, lol.
You have to choose each image you want to associated with each album, and its a tad bit slow if i can remember. But other than that, it gets the job done, im sure there is something out there thats better
If you use itunes there is a program called iArt that downloads everything automatically and embeds the album art in the file itself so you dont have to deal with the folder.jpg stuff (it also has an option to put that in there as well for programs that dont pull album art from the file.)