Ambigram.Matic automatically generates ambigrams, rotationally symmetrical representations of words. I used to be very into ambigrams, especially since good ones were best left to human artistry and not simply a methodical process. I tried making ambigrams of my friends' names in high school, with some success. Some names took a long time to get right, however, and didn't always result in something legible.
If I recall correctly, one book on the subject mentioned software available for manipulating vector graphics to produce high quality ambigrams....
