Lately I've taken to browsing my local Radio Shack and "rescuing" some of the clearance items I come across.
Today I wandered in looking for some terminal lug strips and came out with 60' of hookup wire (can never have too much wire around, right?) and a neat little Velleman Decision Maker kit, both of which were on clearance.
About 15 minutes at the bench, and this simple little kit was all assembled. It's basically a binary magic 8 ball. Press the button and the LEDs flash quickly, eventually slowing down until one of them stays lit.
Not bad for $2.