This is the Critical Hit LED Dice Set available from ThinkGeek ($25). The set comes with d10, d12 and d20 dice that light up when you roll the highest number possible. Allegedly they did their best to make sure the dice are weighted properly, although I have my doubts. Personally, I like regular gaming dice and rolling them the old fashioned way. "Which is?" Putting them all in my mouth then spitting them out on the table. "You're sick." Am I though? *furiously shaking head, spits dice out on table* Because I'm pretty sure my elven archer just survived your pathetic little ambush.
Keep going for one more shot of the dice.
Thanks to Carlos E, who allegedly has a two-sided die. Okay now that's called a coin (and technically still has three sides).