Moebius Strip With Ants (1616x800 Vertical) by M.C. Escher.

Rendered by Knmut Roll-Lund. 1750x3500 Vertical.

Actaestfabula talks about "Moebius Surface" with a funny small comic strip.

Download ATI's rendered and animated screen saver installer file for old Windows (e.g., XP) (requires an ATI Radeon 9(7/8)00 or better). Escher for Real for another one.