Yesterday when Dan and i were at radio shack shopping for his new phone, i picked up a BASIC stamp kit. It's kind of like an embedded system that you program. So far i've made two things. The second i just finished, it's a binary count down. Using six leds as 0=off and 1=on it can count up to 64. It connects to the computer through a serial cable. After it's programmed, you can disconnect it and take it anywhere with the 9volt attached. The programming language that the stamp uses is similar to QBasic (now all those years programming in middle school aren't wasted!). The kit came with a decimal led block too (like a calculator has). I was thinking of adding that to the binary counter, making it able to count to 640 (which is a bit more usable).
Stamp Board (close to actual size)
Stamp (enlarged. This fits into the black socket on the Stamp Board)