I use my agenda as my wallet, but in it I carry a bit more cash, my checkbook, business cards, store loyalty cards, my insurance card, and credit cards I rarely use but do need in certain circumstances.
In my cles, I have my driver's license, the card I use for groceries and gas, and a few dollar bills and coins. I attach my car key, work key, and house key to the outside.
I like this because when I have my whole bag, everything goes in and I do my regular stuff. When I run to get my kids from school, or run to the grocery for just one thing, I only grab the cles and iphone. Both fit in my hand or back pockets, jacket pocket, etc.
It may seem silly, but it always bugged me that I when I only wanted my wallet and phone and keys, the phone didn't fit inside the wallet, and the wallet was kinda big, so I felt like I was still carrying something large. With the cles, it's so small, I can feel like I'm almost carrying nothing. The Cles and phone even fit in my cup holder.