This ultra-thin wallet by Flexy is pretty much as thin as a wallet can get without being invisible.
Made from just one piece of precisely forged titanium, the Flexy ultra-thin wallet has flexible metal tabs instead of leather sheaths in which to score cards. The metal tabs can accommodate up to ten plastic cards or up to 50 cash bills without snapping. The design means this product is a money-holder rather than an actual wallet, but offers the functionality and portability of a wallet in a more compact package.
The wallet sells for around $40, which may seem a bit much for a wallet. However, titanium is used in the best and fastest Air Force fighter jets for a reason -- it's lightweight, rugged and can tolerate plenty of damage and misuse.