I've gone through a number of slim/front-pocket wallet. HuMn (metal plates + rubber band style), All-ett, Koyono Slimmy, the Picharpak Wa-Ben and a couple others whose names I can't remember.

I found the HuMn-style ones to be awkward - too much fumbling around to get the one thing in or out. The All-ett is thin, but a little big and somewhat graceless. The Slimmy is nice, but still a little thick and the corners started getting floppy. The Wa-Ben was my favorite for a while, but I eventually got tired of having non-breathable fabric against my thigh all the time.

So far, my favorite is the Decadent Minimalist DM-1 8-card aluminum. I carry 3 credit cards (2 flat, 1 embossed), license, insurance card, work badge and 2 $20 bills. I have the cash clip, but rarely use it. 3/8" thick, very light.

I might have to check out the Secrid. I'm a sucker for that sort of thing.