I carry an Eagle Creek trifold wallet in my rear pocket. I'm not sure which model it is. It is made of Cordura nylon, a nice forest green color, very durable, and inexpensive. It closes with Velcro. Inside, it has a full-length zip pocket, as well as an open pocket for easy access to paper money. It also has the usual slots for license, credit cards, permits, etc. I keep a book of stamps and a little plastic credit-card-sized yearly calendar in there too. On the outside, it has a horizontal zip pocket for coins. I've had this one for about four years, and it has lasted well.
In my front pocket, I carry one of Jason Burns' Mission Wallets with a Fisher Bullet Pen and a Leatherman Micra or SOG Crosscut. I also keep my work badge in the outside pocket. Inside, I have a small plastic bag with bandaids, alcohol swabs, and a few other small medical items.
The two wallets keep everything tidy and compact. When I'm not working, I sometimes rearrange things a little and only carry one or the other.