I have a Baggallini wallet that converts to a purse or a fanny pack, dependent upon where you clip the strap.
If I'm flying somewhere, I usually convert it to a fanny pack.
My essentials - passport, money and phone - easily fit into this roomy, lightweight wallet. Since it's not too big, it doesn't add a lot of bulk to one's waist - thankfully! Even though this is more attractive than a fanny pack, I'm not guaranteeing that one day you won't see an X'd out picture of me in a fashion magazine under the "Don't do!" category!
Occasionally, I turn it around and use it for lumbar support; I know that my belongings are safe if and when I drift off to sleep.
When I arrive at my destination, my fanny pack becomes a wallet once again. I place it into my purse with the silver lining and I'm ready to roam!