"You use icons, now pay up"
If your company website uses images for navigation and some method of keeping those images visible at all times while browsing the site (like frames or CSS), you are possibly owing Ameritech Corporation money. They own US Patent no 5'933'841, title "Structured Document Browser" which in part reads
When the icon is selected while browsing a document, the browser will display the section of the structure corresponding to the icon selected, while preserving the constant user interface.
They are now testing their claims against the website www.museumtour.com, and if they win, museumtour.com is to pay a license fee for using icon-based navigation. Hey, let's claim to own a patent on website navigation...