I don't think I've actually ever attempted to open one of those heavy plastic packages with my teeth like this rabid-looking dude:

but I have been very frustrated while trying to quickly get to my new purchase inside the seemingly impregnable casing.

The OpenX is made specifically for opening up that hard plastic that is so difficult to cut through with human hands or even small scissors or blades. OpenX may be overstating the difficulty in opening other things (who has ever been unable to open a bag of Doritos?) but that plastic casing is becoming ubiquitous, and I may just have to start carrying one of these around.

OpenX is $9.95.