Gamma world has exciting technological treasures (omega tech), but it also has an extensive Ancient Artifacts table that is, well, puzzling. It has a lot of the kind of items that the writers could see from their cubicles: hand lotion, mp3 players, etc. It’s a big percentile table that was included instead of the 4e rules on, say, charging, or recovering from unconsciousness.
It’s really hard to know what to do with any of this ancient garbage, but nevertheless, during character creation, you spend a lot of time determining exactly which junk you have. I actually chose to forgo a lot of my rolls on the Ancient Artifacts table. Then, during gameplay, we figured out what it could be used for. Ancient artifacts are currency.
We decided that the Dabblers (tech-loving raccoons) run stores, but they’re based on the barter system. You can get something you want (fuel for your motorcycle, ammunition) if you can get them sufficiently interested in the ancient He-Man lunchbox you dug up. We ran an entire barter-based session around acquiring cordless mice and a piece from a nonfunctional microwave from a dabbler warehouse (called “Beast Buy”: one of the players named it as a joke, and the GM went with it).