Jason Kottke, writing on kottke.org, points to Tiny Computers, an iPhone app that puts working miniature versions of vintage machines on your screen.

Ten machines are included: Macintosh, Commodore 64, IBM PC, Amiga 500, Windows 95, ThinkPad, iMac G3, iBook G3, PowerBook G4 and Windows XP. The Windows XP model even crashes from time to time.

See the video below and more on kottke.org.