I have not been to a retreat but did go to what was called an "all day quilt in". Each person as asked to bring a home made treat and the recipe to share. We also had block swaps. There was also a white elephant notions exchange where we could "trade" notions. Everyone was instructed to bring a large brown grocery bag with the mystery notion inside. These were turned in at the beginning of the day. We did not see them again till it was time for the exchange. When the bags were brought out the hosts of the event had added some extra goodies to the bags. After everyone opened their bags and showed off their goodies we were able to exchange bags if we wanted to but had to agree to exchange all contents of the bag for all of the contents of another bag. Only a few bags were exchanged though.