Having just bought the latest Offspring Album - Rise and Fall, Rage and Grace I used Windows Media Player to rip it to my music library but it didn't pick up the album art. I have been using Live Search for finding images lately because it has some pretty handy features.
On the right hand side there are a variety of filters you can apply to the search. Since Im looking for the highest resolution album art for my library (good if your using Media Center) I just select large or desktop and it comes back with the filtered results. I then click the the image link URL where then it opens a new window with the image. I simply drag and drop the Album Art into Windows Media Player and I have my new Album Art sorted. Of course you wouldnt need to go through this if it picked up the album art in the first place..