Depends. I try to avoid checking my bag, so my rollaboard has my clothes, toiletries, etc. If I'm bringing my camera, it goes in there (hard to keep a DSLR in a briefcase!) My briefcase has my laptop, a book, a newspaper, my iPod, etc.

If I'm on an overnight, I use the pillow that I got on the CO DO IV Mystery Tour flight (the CO BF pillow) which is really comfortable. My boss is rather jealous that I've got a real nice pillow to use on flights while she uses the flimsy regular pillows.