Originally Posted by crowe

The magnet method would only work with magnetic media, ie. tape...even with a hard drive you would have to have such a huge magnet you might have to go to the crane at the junk yard. I believe our blackberries have solid state disks which to my knowledge cannot be erased by a magnet.

Good luck with your efforts, but like posted above, the only viable solution may be the sledgehammer erase method and eating the cost, in the long run the cost would be worth it.