I found some videos that test the mechanics of Arma:
http://de.xfire.com/video/a32ca/http://de.xfire.com/video/a3e32/The first video is a good inspiration for a new cheat. Barrel attack. Imagine people running up for a hill and then suddenly facing rolling randomly exploding barrels.
The second just shows that Arma doesn't seem to have inelastic collissions + no friction (-> eternal barrel movements). They should probably fix that for Arma2.