Do you mean a wallet that goes in your pocket or one that will hold your passport and tickets?
While not leather, my husband just bought a strange little wallet that he is LOVING. It's made of sailcloth and has 4 pockets for cards, is deep enough to hold various international currencies and is incredibly thin and flat in his pocket. They do have the same form factor in leather too but it's not as thin.
check out
http://all-ett.com/products.asp
He really did have a hugely bulgy wallet and far too many cards. Now everything fits in this wallet and his pants pocket doesn't look like anything is in it.
I will add my vote for the all-ett wallet. I bought the leather version and the sail cloth version and LOVE the leather one. I have only been using it a week but it holds everything my old wallet but at about half the thickness.
You might also try ditching all those club cards and create one card with multiple barcodes on it. Try this link:
http://www.justoneclubcard.com/
^