Obsolete GUIs Live On at ToastyTech.com
I suspect that Nathan's Toasty Technology Page is a Ghost Site (because a number of its outbound links are broken), but it really doesn't matter. Nathan serves up a wonderfully atavistic gallary of obsolete GUIs (Graphical User Interfaces) that will make you profoundly nostalgic for the days of Deskview, OS/2, GEM (remember that one?), and even such obscurities as Packard Bell Navigator 1.1 and the PubTec File Organizer.
Oh, and I almost forgot: ToastyTech has an incredible gallery concerning the GUI to end all GUI's: Microsoft Bob!