iPhone case or wallet? Speck says you don't have to choose.

Is your iPhone 4 part of your essential EDC (Everyday Carry) items? Are you a minimalist? If the answer is yet, they have a look at the Speck CandyShell Card case. Speck took their CandyShell case for the iPhone 4 and added a rubberized slot on the backside for up to three credit card-sized items. Slide them in, then back out with the thumb release. Simple concept, but potentially pretty useful if you are going out and just want to grab your iPhone, ID and maybe a credit card or two. Available for both AT&T and Verizon iPhone 4, each in three color schemes: NightDrive Grey (pictured), GrapeEscape Purple, and MoonSuit White, each $39.95. How about it: Would anyone out there use this to replace their wallet?
source: The Gadgeteer