Tumi computer bag
I usually make 3-4 trips to Asia, btw 2-4 wks each trip and only take carry-on luggage: tumi bag, trolley bag for clothes and maybe small backpack for shoes, incidentals.
So my tumi bag is pretty filled:
iBook, charger and world-wide adapter, extra CAT cable
Files - as little as I can carry in paper, try to load rest onto iBook
Two flash drives
15gb iPod
Shure E3c earbuds
Treo 600 with usb adapter/charger -USA phone number
SE 520i phone with charger - either Singapore or Taiwan phone number, depending on whether in SE Asia or Greater China
Second GSM mobile phone - whatever is availalble from home - with phone for whatever country I am in (eg China, HK,etc)
Separate Korean cdma phone
Small bag with 5-6 SIM chips in listerine strip boxes (separate phone numbers for various countries)
Two BT headsets (one for phone, one for skype)
Sunglasses in hard case
Extra hard case to put glasses when I sleep on flights
Passport holder with passport, airtix, currency for about 10 countries, few freq flier/hotel cards, extra hotel door cards (many hotels require it for power on in room)
Bottle of water
Meds - besides my Rx meds, some advil, other OTC
Eye drops (again long trans Pac flights)
Extra wrist watch
Pens, business cards
Small pen flight
Hard candy
32 sleeve holder for DVD/CD (to fill up when shopping)
Leather toilet bag filled with everything.
Pair of pj from Singapore airlines - again for long trans Pac flight