I've been promising a Hopf fibration for a logo for years. Suddenly two samples have appeared. The lower left figure was created by Ken Shoemake. For an explanation of the picture, here's Ken's original post to me. (details of picture) or (Large TIFF version of picture).

The lower right figure is actually an associated fibration, the fibration SO(3)--> S^2. This art appears on the cover of the AMS Notices, May 19 97. I need to check its copyright status. There is further information about its details in the Notices issue. Cover story