Total open:
21 credit cards (down from 23 a few weeks ago due to annual fees hitting)
3 debit cards
Carry: Three credit (usually) and two debit cards. The credit will fluctuate depending on what I might be churning for signup bonuses- currently the Club Carlson Visa.
I also have a "truck wallet" that contains a backup credit card, my Kohls card (only store card I use, and rarely), whatever gift cards I might have bought at the grocery store for gas points (currently Lowes, HD, McDonalds) and my insurance cards. I went to a front pocket wallet/money clip a couple years ago due to sciatic pain, and it maxes out at about 12 cards.
I also have three cards that have balances at 0%, but the cards are in the sock drawer with the other unused cards.