Apple's being sued over iTunes.
http://www.appleinsider.com/article.php?id=1143
Apparently the patent maker patented showing “Music/Artist/” and so forth together on the screen for the purpose of controlling a media device.
Amazon patented the one-click checkout... and won an infringement case against Barnes and Nobles' online store.
http://www.google.com/search?q=patent+amazon%20one%20click
Microsoft almost had to pay $500 million dollars to a guy who patented “launching applications from a web browser like interface”... thank God that one was overturned.
http://www.google.com/search?q=patent+eolas%20browser+launch+application