I actually wrote a virtual Round Robin website, but it never got off the ground.

It allowed for multiple Round Robins to run concurrently.
Someone would start a round robin and get the required number of participants.
Then the starter would upload images of all the chips in the round robin.
Once all the images were uploaded, it would be the turn of the 1st participant.
Each participant would select chips they wanted and then upload images of replacement chips.
Then it would be the next participant's turn.
When all the participants had their turn, they would mail the chips they put into the round robin to the starter.
The starter would then mail out the chips to the participants.
Participants would have to include return postage or a SASE with their chips.