I used to use other LEGO elements to separate tightly bound pieces in my collection. My thumb nail and I were quite pleased when I first discovered an actual brick separator LEGO introduced to ease the task. How many styles of LEGO element separators has LEGO made available to the general public?
Bricklink lists two:
There is one other 'separator', but it doesn't look like it's very good for bricks: http://www.bricklink.com/catalogItem.asp?P=x1220
ETA: The Clickits Separator! http://www.bricklink.com/catalogItem.asp?P=clikits021