My wife wanted a Möbius band shaped ring. This is my very first creation.

The one on the right is the final ring, printed with a layer thickness of 0.1 mm. It needed a raft to stick to the blue painters tape (?) that came with my Replicator 2. The raft made the edges a bit rough, so I dipped in in nail varnish remover (acetone) for 5-10 seconds and rinsed it in water.

For more details on the process and pictures of all prototypes, visit http://furboskov3dprinting.blogspot.dk/2013/01/mobius-ring.html

EDIT: I improved the .scad file quite a bit, it and its .stl is uplaoded as moebius ring_4

moebius ring_4.stl printes nicely with 0.1 mm layer thickness and no fill.