I recently purchased the Targus CityGear 10.2" Netbook Case, Black / Gray for $25.00 (in-store price may vary)

Targus CityGear 10.2" Netbook Case, Black / Gray or something very similar (I was unable to find the exact model at Walmart online (TSM148-50))

...what I found is that there is an inner pocket which holds the TouchPad in the official HP case perfectly, the keyboard slips into the adjacent pocket and there are two innner pouches that i found will hold the Touchstone and charger. I found that if necessary I can haul my TouchPad and all the accessories in one fairly smallish case pretty affordably.