Chuck it! - video
Here's the video I was having trouble getting up yesterday...my apologies. Chuck it! is a real fun game ripe with wipe outs, sore arms, and lots of laughs. Click here to see the rules and necessary equipment.
This game would also be awesome, and perhaps better, with water balloons and a sling shot launcher.
Have fun with this and if you find a better way to play or some fun alternatives please let me know!