I have worked a lot with the Vex robotic platform on the 2012 challenge --Sack Attack. Heres a few robots I built.

The arm bot on the left I built to be a demo bot to introduce people to the Vex system. The bot in the middle was the small scooper bot for the VRCC competion. The bot on the right was the large lifter bot for the VRCC competion.

This is the little clawbot kit you can get from Vex. I also added some ultra sonic sensors for experimentation

These are some process pictures of the scooper bot build.