Instructables has directions for making a magnetic wallet/billfold out of an innertube and some old steel. I'm a little skeptical about credit-cards and magnets peacefully co-existing.
Duct tape wallets are non-optimal. The nature of the adhesive used on duct tape results in a wallet that will slowly slide apart based on the forces input to the wallet by your ass. After a year or so, depending on the ambient temperature of your location, the wallet will be falling apart and you will be building a new one. Besides, who needs all those pockets, a full length cash slot or other "wallet" features? In today's modern, RFID, credit-ready, cash-poor society a money clip with credit card and drivers license storage is truly the best wallet you will ever need. Any more storage and you will tempted to store receipts, ATM slips, business cards, and other sundry items in the wallet until you have a full blown case of "Costanza Wallet".
Enter the Innertube Wallet. As a Maker, geek, or otherwise shunned cheapskate, you doubtless have numerous blown bicycle innertubes, a few sheets of rusty 22 gauge steel, and any number of DOA hard disks and their attendant magnets. With such materials and a boundless enthusiasm for turning interminably stored junk into stuff you don't need, I present the bitchin' innertube wallet to solve all your wallety needs.
(via Make)
Update: Matias sez, "My friend Eli in Seattle has been making awesome bags and other accessories from inner tubes and other reused materials for a while. He sells them through his tiny business Alchemy Goods."
