Absolutely, positively guaranteed no matter what:

• Diabetes supplies (enough for double the length of the trip, split amongst two small carry-ons -- glucose meter, test strips, insulin pump supplies, backup shots and vial of insulin in case of insulin pump failure, etc.)
• Emergency food and bottled water (also split)

Less vital (I could live without them ), but never without when flying:

• Dell Axim X30
• Motorola MPx220
• Nintendo DS
• Creative Labs Zen Micro 4GB
• el-cheapo Sony earclip headphones
• Kensington AC/Car/Air iGo-alike, with iGo's iTips adapter and tips for above devices
• Reading material (usually the latest copy of Scientific American plus the book of the week)

I usually have my Canon S70 camera with me, as well (especially if I'm going on a roller coaster credit run), and frequently but not always my Sony PCG-R505JSK laptop.

For lengthy trips, the Zen Micro gets replaced with the 80GB Zen Xtra, and I also toss in the 30GB QCool digital wallet to back up the camera.

I realize that there's some duplicated potential in there (that phone is a decent PDA, both the phone and the PDA can play MP3's, etc.) but each device still does its primary function better than some other device "just filling in"...

Vital items in my carry-on bag, in no particular order

Book
Case for my hearing aids
Cotton buds (vital for itchy ears)
Spare underwear and maybe clothes and shoes (depending on whether I checked a suitcase or not)
Handbag (to save me carrying it separately)
Anti-histamines and anti-baby tablets
Nail clippers
Torches
Trasers
Hair brush and hair essentials
Printouts of all bookings
Empty vial so I can collect any interesting item I come across - insects etc.
Binoculars
First aid essentials
Large woolen scarf 1.5 m x 1.5 m with antique brooch which can serve as blanket, umbrella, picnic rug, dressy shawl, swag, tent, padding for fragiles, sling, bandage, or any other applications I can come up with (a true Hitchhiker would carry a towel for this purpose but my scarf is more elegant)
"Qantas cloths" - the cotton disposable towels provided in Qantas Club bathrooms

My handbag (inside the carry-on) contains:
Pens
USB memory key
Hearing aid batteries
Bag for hearing aids
Carry bags
Small torch
Nail clippers
Pocket knife (removed when flying)
Comb
Small vial for specimens
Cough lollies
Lip balm
"Qantas cloths"
Keys
Hair clips
Purse

My purse (inside my handbag which is inside the carry-on) contains:
Money
Credit cards
Rain scarf (one day someone will invent water-proof hearing aids! Please?
Emergency numbers
Comb
Postage stamps
Assorted membership cards - museum, health insurance, frequent flyer etc.
Zip-lock bag for specimens or hearing aids

My passport and spare credit card reside in an internal pocket of my clothing where they can only be accessed by removing my clothes.

Mr Falconea carries his camera, laptop and lots of spare batteries.

Audrey

Alienware Area 51m
Ipod,Shure e3c's
Sony PSP

OMG...

Tumi laptop bad usually contains the following:

HP DV1170 notebook
Remote control for above
External 80Gb drive with all major backups and images of all my important CD's
SonyEricsson cellphone
Blackberry 7290
Motorola HS850
Igo with 2 dualpowers and dualpower splitter with around 20 different tips
Archos Gmini400 mp3 player
Microsoft notebook mouse
Shure headphones
Dell Axim x50v
USB cables for external HDD, phone, Blackberry, Dell and Archos
Bunch of SD and CF cards with video content for PDA
Fuji camera with bunch of xD cards
Creative labs webcam
Thinkoutside Bluetooth mouse
Thinkoutside Bluetooth keyboard

And loads more depending on the trip

Using Internet Explorer, add the pages you want to make available offline to your favorites folder. Right click on the favourite you would like to read offline and select 'Make available offline'. You can also select how many links deep you want the backup to go. Do this for all favourites you wish to read offline.

Now you can goto the tools-synchronize on the browser and either setup a time to do the synch or just press synchronize to do it immediately. If I have an early morning flight I set it to do it a couple of hours before I wake up.

One piece of advice, you will want to goto the tools menu and then internet options and adjust the temporary internet files settings to a large number to handle the amount you will be downloading. And when I am done reading I regularly go to the same menu and delete the files, make sure to click the 'delete offline content' button to free up space.

I haven't used the tool that copwriter suggests, but it looks good.

Happy surfing!

Incase PowerBook Backpack
15" Apple PowerBook
20 GB Apple iPod
Power Adapter
Airport Express
iSight
Canon PowerShot SD500
PalmOne Treo 600
Book
iKlear
Macally Travel RJ-45 Cable
Other cables

So it seems like everyone carrys some sort of iPod, Headphones/earphones, and some sort of reading material. . .

Whats on your iPod?

Using the Shuffle yields better battery life. I carry similar, a LifeDrive instead of the Treo. Play games on LD, work on laptop and listen to tunes on Shuffle and I have enough battery life on all my devices.

• Dell Latitude laptop.(soon to be a Dell D810)
• Ipaq 5500(will be replaced with a hx4700 tomorrow)
• Sanyo 5150 cellphone (replaced by an Ipaq 6500 or Samsung i730)
• Bose QC2
• Igo Juice70
• Logitech Cordless Optical mouse for notebooks
• Kensington WiFi Finder Plus
• Kodak DX3900 (Soon to be a Canon 20D)
• Network cable for hotels that provide a RJ45 outlet only.
• USB/12VDC cable for Ipaq

Well no Ipod for me. Thats just something else I'd have to carry. I use my Ipaq and a number of multi-GB CF cards for music.

Vials? specimens? Are you perhaps an entomologist?

Well, I'm a a serious amateur marine biologist and general amateur naturalist.

This is the sort of thing that happens to general specimens: http://www.bluering.org.au/leon/feature-7.htm

And just to stay on topic - a digitally "enhanced" image of a Qantas plane being destroyed by a cone shell: http://www.bluering.org.au/leon/digital-2.htm

Audrey

Also, Howard Leight NRR31 ear plugs.

Soft.

Comfortable.

Indispensible.

^

. . . . . bump . . . .

iPod
Noise-cancelling headphones
Sony VAIO
Sony Ericsson phone
Canon EOS 300D
Webcam
Sony PSP
Various cables, cards, discs and adaptors
Books & magazines
Toiletries
Tickets and other travel dox
Cards, money
Keys, coins
Business cards, paperwork etc.

And more!

Let's see. In my bag (LowePro laptop bag), you'll usually find:

Laptop (Thinkpad T40)
iGo Juice power supply with three PPS cables and tips for cellphone, PDA, BT headset, and generic USB tip for iPod.
iPod (with iTrip for rental cars and a cassette adapter if they've got a tape deck)
Shure e3c earphones with tri-flange tips
A mini-sleeve with 6 DVDs (if it's a long trip, more will be in with my clothes)
A little gooseneck LED light I got at Fry's that runs off USB, 3xAAA, or cigarette lighter port.
A couple of books (again, if it's a long trip, more in my main bag)
A little camera (Casio Exlim) for business trips where I might get a little sightseeing
Motorola v600 quad-band phone unlocked
HP iPaq 3850, maybe with Bluetooth expansion pack.
aluminum clipboard cover and a few file folders for work stuff
Pens/pencils galore (since I always lose them)

All of the little stuff is kept in 2 United business class amenity kit bags, which are perfect for this sort of thing.

If I don't know where I'm going, my Magellan GPS with serial/USB cable to hook into the laptop for maps.

Added the following this week:

Black Motorola Razr V3
Blue 6B ipod mini
1Gb ipod shuffle
Etymotic 6i's