I started working on a new robot, using the same circuitry as the sandwich robot (eventually, I'll have to learn something more advanced than the line follower circuit :)
Instead of a line-follower, I am trying to make it a, what's it called, photovore. I got the idea from David Cook and his XS Boost Chef's Salad Robot on his website, robotroom.com.
Mine, however, will run on batteries, and the antennas will just be little red lights. I plan on adding whiskers for object avoidance, a piezzo buzzer, and a tilt switch I salvaged from a toy.
I tried building this robot earlier, but I messed up somewhere and for the life of me could not get the thing to work (I think I burned out some of the electronics). So, in frustration, I salvaged all the components I had not destroyed, bought some new ones at Radio Shack, and rebuilt the robot. I have just now gotten to a point where I believe the robot will work. If all goes well, I might have this robot completed by the weekend.