John Chan [madox] did a nice writeup of his first experience with Shapeways: designing a mechanical iris diaphragm. John writes:

[…] I set out to design something in the shortest amount of time and yet would still give me a good ‘feel’ of what 3D printing is capable of today.  The time constraint was probably also due to the fact I read about the offer at midnight and wanted to send it to print before I sleep 🙂  Result? Concept, Design, Upload, Ordered all within 2 hours!

Very cool! Any chance of a video showing the diaphragm in action, John?