I never carried a purse pre-kids. I kept everything in my backpack and if I was going somewhere w/out my backpack, like out at night w/ a friend, I shoved money, ID, and bank card into my jeans pocket (I never wore anything but jeans. lol)
Now I have a big old diaper bag. I have a wallet, cellphone, tissues, pads (of the feminine variety), keys, pens, cell phone charger, and hand sanitizer for me (and possibly them.) Kid stuff I have is diapers, wipes, baby's Benadryl and epi-pens, and toy cars. Sometimes i have extra clothes or underwear for the little ones in there as well. When I go somewhere w/out the kids, I take my wallet and cellphone out, but I feel awkward carrying a wallet--too big to fit in a pocket. Much better now that it's cold and I can shove it into my coat pocket.