This is the $13 D20 Bowl Set available from ThinkGeek. Together, the two pieces form a D20 die. Separate, they form two halves of a D20 die that are fillable with chips and dip. Don't limit yourself to chips though, you could also fill them with candy like fun-size Snickers bars or Sour Patch Kids. Or nuts! Not mine though, mine wouldn't fit. I'm not bragging, by the way, it's a medical thing. Just kidding, I was bragging!
Keep going for the bowls forming a whole D20 Voltron-style. Then roll it off the kitchen counter onto the floor!