Tear-It!!, as the name suggests, will let you tear any selection as if you tear paper! You can achieve these effects with any picture you like, text or shapes. The download includes a Photoshop ATN file with five actions, also a PDF help file with screenshots on how to use it. Achieving the effects is as simple as selecting your layer and running the action!
The effects included are (see preview image and screenshots for examples):
-Subtract Selection (tear) -Cut-out -Outline -Depth -Edges Only