If following simple directions online in order to make a duct tape wallet is somehow too sophisticated for you, take a look at this Duct Tape Wallet Kit. myDuctBills shows you with a printed manual (complete with pictures!) how to make a wallet out of duct tape, and even gives you all the materials you need. Yes, materials such as duct tape.
The kit also comes with three bits of colored tape in order to stylize your end product, because really, people with duct tape wallets care loads about how their wallets look.