So, after trying to make an standalone urban PSK work, I realized that I could actually just combine most of the contents into a wallet - something I already pretty much have to carry every time I leave the house. Here's what I've come up with so far, which is by no means final and by no means the end-all-be-all. These are ideas for a starting point-- some may or may not be useful to you. Oh, and know your local laws. Anyways, check it out.
This is an Eagle Creek bifold I've had for years. Pretty average, non-descript wallet. I could have just loaded up one of those giant Maxpedition/Spec Ops wallets, but that's too easy, and too bulky to actually carry around anyways.
Comparison shot next to an iPhone 3GS. The wallet's a bit thicker, but not too much. Easy for me to front pocket carry.
Shivworks Lil' Loco, a ferro rod and a half-spool of Kevlar survival cord from SerePick. The Lil' Loco's kydex sheath is pinned into the wallet and the knife can be drawn quickly, one-handed. There's about 8-10 feet of cord on the spool - it is very strong and has a 135lb test strength. There's still plenty of space for currency or whatever in this pocket.
SerePick stainless bogota picks, held together by a small spring from a mechanical pencil. The safety pin can be used to attach the picks to you clothes, concealing them pretty much wherever. Don't remember where I saw this trick, but it's a good one. The bogotas are awesomely made and small enough to hide pretty much wherever. This stuff takes up minimal space in the slot, so there's still room for a couple cards.
And in another one of the card slots: two more safety pins, P38 can opener, and gorilla tape wrapped around one of those little keychain membership cards. Still room in this slot for a card to two as well.
Not pictured - a couple bandaids that I forgot about until now.
So, there you have it -- my take on an urban PSK. Even if you've got no interest in adding this much stuff to your wallet, you can take some of the ideas and tricks and apply them to your own situation.
The hacksaw blade is super thin and handy, and you can pick up two for like $3 at a hardware store. If you're into lock picking, the bogotas are awesome and just disappear in your wallet. There are even smaller ferro rods that likewise disappear along the side of a credit card slot. The Loco is pretty cool, but there are lots of other designs out there that would work, like the credit card style blades from Spyderco, Microtech, Snody and others, I'm sure. Heck, even a razor or exacto blade could be handy.
I really like using a wallet vs. a standalone kit for a number of reasons. It's a pretty painless addition to an EDC rotation; you've got to carry your wallet anyways, why not add some extra, useful tools to it? It's also pretty grey man - everyone carries a wallet, so it's not going to raise any eyebrows or draw unwanted attention. If someone mugs you and takes your wallet, then you're out all of this extra gear, too. If you're concerned about getting mugged, maybe take a look at a money belt - you could conceal most of this gear in one without too much trouble.
I will have more detailed posts about the Lil' Loco, bogota picks and survival cord in the near future. Keep an eye out.
I'm still thinking this through and refining--planning on adding a mini pen of some kind and maybe a pre-threaded needle. Thoughts, suggestions and ideas are welcome in the comments.