I've been holding onto this pattern from Bolt Neighborhood for quite awhile now.
I had some leftover fabric from my tote bag I take everywhere now, so I decided to make a matching wallet.
I added a tab on the side with a key ring. Then I attached a key ring to the strap of the tote bag. This way I can remove it whenever I want, and the wallet can be hidden inside the bag, but still easy to find.