The HVW Technologies' Stamp Stack II is a bread-board friendly, abuse-tolerant, Parallax BS2 100% compatible microcontroller.
The SolarSpeeder 2 Kit is a very quick Solaroller that can cover 3 meters (10 feet) in under 40 seconds in direct sunlight.
This new version of the Photopopper is still a solar-powered, light-seeking, obstacle-avoiding robot, but now with update electronics & gold trim that make it twice as fast!
The Secret L293D motor driver kit replaces the guts of a standard servo and turns it into tidy gear motor with a built in motor driver!
The L298 motor driver IC is a very popular, but hard to use chip. Our Compact Motor Driver Kit tames this beast, and adds useful functionality!
Our demobot shown built with GM3 motors (since replaced with GM2) on an Sintra base (extra).
These aren't kits, as much as they are an inexpensive bag of components so you can build yourself a Symet.
Herbie the Mousebot is a very quick, easy-to-build, light-chasing robot kit with functional whisker and tail sensors!