I'm another one with a 12" PowerBook. (Well, right now I'm on my old 17" Dell Inspiron because my PowerBook is about to go back to the Mothership to get a new hard drive, but ....)

What I carry with me varies by mood and purpose, but this is pretty standard:

In a backpack of some sort (I have several and it just depends on my mood, mostly) which I don't wear on my back, but sling one strap over my shoulder to and from the car --

My 12" PowerBook in its Wakefield/SFBags sleeve.

My Canon PowerShot because it's small, and I like to sometimes snap pictures of silly things or odd things (thus I have vacation pictures of plates of food and toilets and views from loo windows, among other things). The good thing is it's small and the bad thing is it uses AA batteries and frequently needs fresh ones. Hopefully that's something else I have with me, four extra batteries. Not always, though. My husband gave me a much nicer camera for Christmas but it's large enough to be cumbersome in the backpack and I haven't figured out a workaround for that. It uses a battery pack, so I may end up carrying it, anyway.

iPod and headphones. My new ones are Sennheiser that I bought at the Apple store (http://www.sfbags.com/products/ipodpouch/ipodgearpouch.htm">http://www.sennheiserusa.com/newsite/productdetail.asp?transid=500426[/url]) that fold down into a small plastic case that fits in my iPod gearcase ([url]http://www.sfbags.com/products/ipodpouch/ipodgearpouch.htm) along with my iPod, cables, converter and plug, etc.

Books that I'm reading, either for reference (SAVE THE CAT, a screenwriting book I'm using right now, GETTING THINGS DONE, to skim when I need to figure out something) or the novel du jour (right now, SKINNY LEGS AND ALL by Tom Robbins). That loads down the pack.

Whatever work stuff I need with me -- scenes printed out to read and ponder before I dive back into the computer. I still end up printing stuff out to read and mark by hand. I write on a computer but edit/ponder the old fashioned analog way.

Some sort of pads for writing and taking notes -- legal pad or smaller, perhaps a spiral, whatever is handy when I'm walking out the door.

Pocket Moleskine for "capturing," and 3x5 index cards in its pocket for contexts.

Dog treats.

Post-its and highlighters for marking up reference books.

Makeup.

Breath mints.

Then I have a small purse/planner which I can put inside my backpack, or pull out and use if I'm leaving my backpack in the Element. It contains:

Small Franklin planner pages which I use to list NAs that I'm working on that day, plus address, contact notes, ongoing notes for ongoing projects.

Credit card, insurance cards, driver's license, Starbucks card, etc.

A few more 3x5s in case I need them.

Two pen-loops -- one with my Lamy Safari and one with a gel pen.

Post-its/post-it tags.

Money.

Lipstick.

Keys (unless they're in my pockets).

Cell phone.