We found this super cute idea online at Martha Stewart.com. It is from the 12/07 issue of Martha Stewart Living
Invite young friends to gather around a table made of snow. Tightly pack snow (wet snow works better than the powdery kind) into two large galvanized tubs, and leave it overnight to harden. Overturn one tub, unmold the snow, and then overturn the second tub on top. (To ease the way, set the frozen tubs inside a garage or a shed for a half hour to warm the snow.) For a seat, use the same trick and a 5-gallon bucket.