The infamous crustless peanut butter and jelly sandwich patent is the other silly one that springs to mind:

(http://www.google.com/patents/US6004596)

I don't think the swing patent was granted, but this one certainly was. And was only challenged in court when the multimillion dollar company thought it could stop other companies making crustless peanut butter and jelly sandwiches. In 2005.

paywalled WSJ article which I can't read (http://online.wsj.com/news/articles/SB111298192348602162)