There is some interesting work going on at the University of Pennsylvania in modular robotics. Some of the efforts in the Modular Robotics Lab are pretty cool. The video of the self-reassembling robot is definitely worth watching. Make sure you watch it all the way to the end - the last 10 seconds are worth it.
I personally like the part were the robot just falls apart after standing up. Also would there be rules the exempt these robots from the rule that states that you cant have your robot leave things on the field deattached from the main body of your robot.
I had the opportunity to hear a Mark Yim lecture and speak with him a bit when I spent a summer at UPENN. He is a very interesting guy and is working on some neat projects (which he began a while ago at Stanford and PARC). He also teaches a course called “Mechatronics” which has some similar elements to FIRST and MIT’s 2.007 (you can read an article about it here).
I also visited the GRASP lab a few times and saw some of the projects they are working on there. You should definitely stop by if you’re in the area (the people there will probably show you around if you are genuinely interested in their work).