This nifty wallet was just what I needed when I didn't want to go out carrying the whole of my bag.
It fits coins (in back pocket), notes and cards. One of the two notes pockets fits my iPhone just fine.

All the how-tos are on line at DixieDIY.com - there's some great photos in the how to section too.

Once you've made one, the second is oh-so- simple.