Cles. The first accessory that I got. Before I got my wallet I used to carry my license and change in it and would just grab it to run to the store instead of carrying my bag. I still keep my change in it. And today I ordered the cosmetic pouch for feminine things and such. And there's a little pocket inside I can put my keys.
I use my clés (I have a few), round key holder and agenda every day, so they're probably my most practical SLGs, after my wallet.