Everyone brings a gift. It should be an item that's too good to throw out, and to crappy to keep. It could be anything. A game, a music CD, a figurine from Aunty Em, anything. It is unnecessary (and sometimes important) that the original owner does not identify herself.
Every one will draw a numbered slip of paper. On the first turn, person #1 chooses a gift, opens it, and it is admired by all. On the second turn, person #2 gets the choice of "stealing" any unwrapped gift (#1) or choosing a wrapped one. On the third turn, person #3 gets the choice of "stealing" any unwrapped gift (#1 or #2) or choosing a wrapped one. Game continues based on the following:
At the end of the last turn, person #1 (who had no informed choice at the beginning) can choose to put back his or her gift and steal any gift that is still available (see step 4 above). Then the gift "exchange" is started again (see steps 3 and 4 above) and ended when someone either chooses or is forced to take the gift given up by person #1.