So, what's there?
Well, I have my iPad -- it has TONS of RPG pdfs on it (S&W Whitebox, Kellri's books, my Wilderness Alphabet, The Dungeon Alphabet, etc.) Plus, it has wifi, so if I need something on the interwebs, I'm good to go.
I have a pencil (gotta have that) and a printed copy of level 2 and a map that I pieced together using tape. How old school is that? ;) Also some pre-generated Henchmen and some tables I borrowed from the blogs like this one and that one.
I also have my dice -- I have a bunch of color-coded RPG dice. I often have new players and my grandkids, so it helps to be able to say "roll 3 green ones" if I have to. Sometimes it's hard to describe to untrained eyes how a d8 looks different than a d10 or d12.
I have some plastic chips (just in case). I use them for luck points or fate points or whatever. Uses for potions. Charges on some 1/day items. Whatever.
I have my bag of Scrabble tiles. Very, very useful for NPCs, monsters, etc. I use a battlemat, so I have some wet erase markers too. You can see the corner of my DIY battlemat (grey) by the iPad.
Finally, the plastic trays hold a variety of pre-painted plastic minis. Mostly humanoids and undead (my faves). The screen is from 3e and it has no info on it that I use. It just has pretty pictures on the other side and it was $1 at the used bookstore. I plan to replace the interior text with info from S&W -or- I may glue clear plastic pouches on the interior so I can swap the GM info out when needed.