We have all had that problem. You are taking something apart and then the last screw strips itself. In this indestructible i will show you two different ways to unscrew a stripped screw.

Step 1: The Poor Mans Way

This first option uses 2 things. it is the cheapest way however you still will not be able to use the screw after unlike the second option.
You will need:
A screwdriver (one that fits your type of screw)
A rubber band (preferably one that is nice and wide)

1. The first and only step in this process is to place the rubber band in the screw head, insert the screwdriver and undo the screw like you would normally.

This works because the rubber band fills the holes dents and grips the metal while you unscrew the screw.

Step 2: The Slightly Richer Mans Way

This second option uses only one item. After completing this option you will be able to use the screw again, only this time it will be a flat head.
You will need:
A Dremel (or you could use a hack saw if you don't have a dremel)
Cutting attachment (only if using the Dremel)

1. Again this is the only step. First fire-up your Dremel, next we need to make a single straight cut across the top of the screw. After this use a Flathead screwdriver to unscrew the screw.

if necessary you could use a rubber band (like option 1) to help with the removal of the screw. This screw as long as it isn't bent can be used again.