I almost always leave my house with a small magic backpack. It usually includes a bicycle , a gimmick deck, smoke by Alan Rorrison, TT, Tarantula and Dresscode.
For occasion on when I am leaving the house on a wimp I bring my ring for Divorce by Justin Miller and Ring Thing by Garrett Thomas , 3-4 quarters, and spider pen/ loops. These few items allows me to perform a endless amount of effects and routines without having huge pockets.

A deck of cards, usually prepared... but willing to ignore my preparation if the whim takes me. And whatever packet trick I am enjoying at the time. I have no qualms about producing random items from my pockets: I teach in a school, and the pupils kind of expect me to entertain from time to time with weird gizmos. It gets around a problem mentioned somewhere else of how to introduce a prop that is obviously not a normal piece of life too!

-Deck of Cards
-Invisible Deck
-Rubber bands
-Half Dollar
-Extreme Burn 2.0
-Kolossal Killer
-Inner Circle

...and I alwasy have two small packets of business cards set up as a mini-Svengali deck (with short cards) and an Invisible deck (just put raised lettering face to face) ready in my wallet so it' s always fun to give out my card.

I like to keep a few coins from whatever country I'm in inside of the change pocket of my jeans. I've got a fairly decent one coin routine that I can turn into a coin under watch/watch steal in an instant if I want to. I also carry a pen with me, and will use it for writing things down in my daily life (or use it for Gregory Wilson's Recapped routine). Am I at a restaurant or bar? Great! Impromptu spongeballs for paper balls over the head or some in the hands magic. In a bar setting I'll make all sorts of assorted objects disappear with simple vanishes from Bobo/sleeving. Add some put-pocketing and a bar bet or two and I can entertain for more than 10 minutes while really only needing to bring a pen and a watch around (everyone has coins!)

I almost always carry a phoenix deck & some coins to practice with.
Sometimes I also take an ID with me.

2 Decks of Cards
Jumbo half Dollar
Ace
Puncture 2.0
rubber bands

Changes day to day

Always a TT and a business card trick. Have kept these in my pocket and wallet for years. Just for those one in a hundred times when I can use it.
Richard

Its nice to see people posting in here almost 12 years later.

I love thinking about this topic. In my wallet I have Heiny 500, Powerball held together with some rubber bands. I also have a bill for Asi Wind's Time is Money. I ALWAYS have my wallet, but I also like to carry a coin purse with 3 coins and a shell and a sun/moon coin for SAMOYA. Exact Change is usually in my other pocket. That's it; but that is plenty.

Finger ring, holy moly, coins, a deck of cards or sometimes Monte cards in a z fold if I don't want to carry a deck. Loops often but not always

Deck of cards tuned in Mnemonica, ready for Michael Close's AMAZING invisible deck routine. I could go into other effects afterwards due to the condition of the deck. But most of the time, the ID is more than enough to convince whoever happens to ask me to see something. And also I do think that it's normal for a magician to carry a deck around wherever he/she goes.

A deck of cards set up for Red Hot Mama wrapped in some elastics.

Four silver half plus [, Scotch and soda, copper silver, thumb tip, four different coins in a pouch that I like to play with and bang ring

I have enjoyed reading what others are carrying and using. Myself I carry the following money magic.
Tembus so simple but has never failed. Two Dollar window, Wonderland Dollar and papercliped Dollar. Scotch and soda and a couple other coin tricks. Along with that melt down, cut and restored string.Power ball 60, Plus.chip prediction.these are 10 of 30 that I switch out regularly. Plus some mentalism and objects around me. Every magician is different and their favorite effects very. No matter your favorite or any magicians favorite. Remember the magic comes from you and your personality that make the magic.not the trick itself.

Odd Quad by Daryl, Mental Photography, Vernet TT...maybe a Coin Unique from time to time.

Index cards, a swami gimmick, a couple bent coins, and a quarter shell in my pockets. My wallet has a great instant-reset borrowed bill TnR I made (based on Ammar's wallpaper tear card restoration) along with a gimmick for peeking full-length credit card numbers (I suspect it's an original idea).

2018 :
rubber bands
regular coins (at least 3 of similar denomination)
note bills (for change)
tt (loaded with a bill)
wallet (regular or gimmick or my toad skin wallet (a real dried buffalo toad)
ball pen (with a cap)
ring (possibly pk)
business cards
candies (for personal consumption or impromptu transmutations)
smartphone
a possible additional gimmick or trick I m working atm or upon mood

Posted this befor, someplace;; for you who have people asking "do a trick---do a trick---do a trick --over and over -and over---ASK them for a coin or $ bill-- do an effect with the coin or bill - then put Bill or Coin, in YOUR pocket - if they ask ?? say "I do this for a living-my Family Thanks You"- of course, if their BIGGER than you or they get MAD - just give it back L-O-L (80 year old reTIRED-70 year Pro)

TT
Mini chop cup
Deck of cards
Hal Dollars
Ring and string

and sometimes a little packet trick (nfw, double back, gypsy cards)