If you're offering data destruction up as a service, it's hard to go wrong with a $30 drill from Harbor Freight and a 3/8" bit. Cheap, fast and easy. I would take the high-grade board off the drive *first*.

If you're into that sort of thing, when you dismantle them there are some pretty powerful magnets inside that apparently have value on the eBay market. The magnets are powerful enough that you definitely don't want to get your fingers pinched between two of them.

--Geoff