For true DIY, hack the included cassette mechanism into a solar-powered device using the high performance Miller Solarengine which converts light into impressive bursts of energy! High performance, SCC3733-MSE version.
Looking for a more flexibility out of your Sumovore, but you're not too up on programming? The PICAXE is a PIC-based solution, programmable with flowcharts - and we've added it to the Sumovore!
This clever "spring-in-loop" sensor configuration is a well-proven touch-sensor for small to medium size robot applications
The BoE-Bot Robot Kit (USB) is a complete mobile robotics kit.