RepRap stands for Replicating Rapid Prototyper. This means it is a robot (a Cartesian one), which can replicate itself.
This is a very cool project, and as a (future) mechanical engineer I can't afford not to participate in this!!
This is the future!
TinTin or 'Kuifje' being my youth hero I had to print this. (Also own design)
This is the first object I designed that was printed by someone else: http://www.thingiverse.com/derivative:349 And I must say it's very exiting to see other print your stuff!
I think this is an interesting design, as it is a very technical design. You should realy check out this website by Juan González Gómez. It's about a snake build out of modules like this, very interesting!