Timbuk2 Bags - Classic Messenger
Holds all the crap listed above and can take a serious beating.
I like how these came back into style. I hope they never go out of style and even if they do I'm still going to rock them!
For cabbies, the Tush Cush is the new beaded seat cover. It looks dorky but it gives me height so that I can intimidate my passengers better. It also keeps my back from killing me during my twelve-hour shifts.
Essential. The best map of NYC you'll ever buy.