[sweetspot]

Colin, you're asking for trouble. This is a really horrible idea IMO, as you might risk:

Exploding the battery
harming yourself
harming someone else.

If you manage to somehow drop your DAP, and it lands on something which can potentially puncture the battery seal, you might see it catch on fire, or perhaps have the innards come flying out of the iRiver case and land on someone's skin.

I really don't think that this sort of thing should be encouraged at all, as there's a very good reason why batteries are not made to be like that, and are very well protected in their alloy cases.... In fact, I think it's pretty irresponsible to do such a thing, because you CAN hurt someone.