Punctured Drum
Goal: fun

Materials: 5 gallon drum (or other large container) with small holes punctured in the bottom, smaller bucket, easily attainable fast flowing water supply
** For however many groups you have, you need one of everything for each group.

Activity: Split the girls up into pairs, one girl holding the punctured drum the other holding the smaller bucket.  The girl with the smaller bucket runs to the water source, fills it up, runs back to the drum and pours it in.  She continues this until the punctured drum has overflowed.  The team who'se drum overflows first, wins.

Adaptions:  You can have larger groups of girls per team.  The object this way is for the group to fill the drum to overflowing by using portions of their anatomies to plug the holes.  You may draw them out of a hat and switch in the middle of the game to make it more interesting.  Or, you may pick each girl to have a different part of their body to use through the whole game.  This can be adapted in many ways you choose.