I found two extended battery cases, currently sold only through Hong Kong distributors, which really tickled my pink ...
Here's the first: supplemental 3200mAh battery built-into an integrated back with front flap and metal kickstand.
Here's the second: supplemental 2600mAh battery built-into an integrated case with front flap and metal kickstand.
I ordered the second one and should have it by the middle of next week.
The primary difference between the two seems to be the connection between the phone and the battery (the first is constant, the second is on-demand) and the increased side/corner protection offered by the second case.
They are both available on eBay ... I'll let everyone know how my purchase experience goes.
p.s. This should probably be moved to the Accessories Subforum ...