In Just Cause 2 for PS3 and Xbox 360, there is a rather silly weapon called the bubble blaster. While it does no damage, if you shoot it toward police it will increase your heat up fairly quickly.
It can be found near coordinates 4246 by 25960. In a field you’ll see a small bell tower. Climb to the top of the tower and you’ll see the bubble blaster sitting on a small table. It has limited ammo, so only use it when you need heat.