Over in the Google+ 3D Printing group, a guy named Mark Whedon has been experimenting with something he calls Velocity Printing, which basically entails creating images on the surface of a print by varying the print velocity. The vase below is clear PLA with the speeds set to 35 mm/s and 15mm/s. It's very cool and I'd love to have something similar incorporated into Simplify3d... a long shot I know but seriously, this is cool.
https://plus.google.com/+MarkWheadon/posts/Ya345SGoTSn