The cupcake from makerbot is a great kit , I spent about 40 hours all up building it across a week (getting little sleep and RL, the GF and a full time job just kept getting in the way 🙂 ).
The mechanics in the cupcake are easy to assemble and the instructions on their site are a great reference as you put it together.
The electronics were a far more serious task , as they are surface mount you need a magnifier and a steady hand.
All in all a good kit and would recommend it to reprappers who want a complete kit that they can just get started with.
Via RepRap Builders and Flickr