Our immediate reaction to Incipio's Stashback for iPhone 5 ($40) is that it's like just like Speck's CandyShell, plus a wallet. The co-molded rubber and plastic case is actually pretty cool: not only does it provide thorough protection for your iPhone, but the bottom flips up, serving two purposes. It can be used to accommodate accessories that don't otherwise fit, and it also provides access to the rear compartment that can hold up to three credit…