On a day to day basis, I have:
Front right pocket: Keys, cell phone, pocket notebook, Swiss Army Knife (accept no substitutes)
Front left Pocket: iPod, various pieces of paper with info I have to keep with me, Challenge Coin.
Back right pocket: Wallet with ID Card, driver’s license, money, etc.
Right cargo pocket: Reflective Belt. +10 against automobiles. -10 against everything else.
Left cargo pocket: Liquid energy. Usually a can of monster or a couple little cans of coffee. Also usually temporary until I sit down.
The pockets to get a little “full” with all that stuff, so usually I take the notebook, phone, wallet, and iPod out of my pockets when I’m at work and just keep them on my desk until I get up. If I’m wearing my newer uniform, the cell phone and iPod move down into the cigarette pockets on my lower legs. (Look at those pockets on the ABUs, and try to convince me they could have any possible designed purpose other than holding cell phones and smokes).
If I need to carry more stuff every once in a while, I’ve got a cheap little backpack or a laptop bag that I can move up to, but both normally stay at home.
EDIT: Oh, and as for keeping track of all that stuff when I take it out of my pockets (or when I’m not wearing pants, which is usually only at home), I’ll invert one of my uniform caps and just pour everything into it. My wife says I’m weird, but she admits it is a system that works for me.