eZer Way (Using Flash)

New Flash Document > File > Import > Import to Library

Now that you've imported your SPRITE SHEET into the library drag it from the library into the stage then do this:

Modify > Bitmap > Trace Bitmap > 100, 1, w/e, Pixel

Now just click on the background and press "Delete" on your keyboard. And all of your sprites are now perfectly seperate from each other.