For all you gear-heads out there, since I often get asked what equipment I use and carry with me, here goes...
A LowePro Vertex 200 AW camera backpack loaded with:
Canon EOS-20D IR - converted to pure infrared capture
Fuji FinePix S200EXR (as a backup body - not always with me)
Tokina AT-X PRO DX 11-16mm f/2.8
Canon EF-S 15-85mm f/3.5-5.6 IS
Canon Speedlite 430EX II Flash
Several extra Canon LP-E6 and BP-511A batteries
Canon TC-80N3 Timer Remote Cord
Hoodman HoodLoupe v3 with custom bracket
Zoom H4n Sound Recorder
Numerous Lexar 4GB 300x, 8GB 233x and 8GB 300x CF Cards
Gitzo Explorer 6x Carbon Fibre tripod with Manfrotto Hydrostat 468 MGRC2 ball head. Manfrotto 701HDV video head.
For downloading and processing images while traveling, I use an Apple MacBook Pro 15.4" laptop with 4GB of RAM and a 500GB 7200rpm HD, Adobe Lightroom v2, Photoshop CS3, RAW Developer and PhotoMechanic. Multiple backups of my raw images go to several portable 2.5" FireWire hard drives.
The camera bag weighs in at around 12 kg (or 26 lbs) - not including the laptop! When I'm hiking any kind of distance, I also carry 1-3 litres of water (another 1-3 kg, of course), a GPS, compass, snacks, jacket, etc.
I have taken this amount of gear (more when I was still shooting with film!) on fairly long 16 km (or 10 mile) hikes in Canyonlands and Bryce Canyon during hot summer days. It is not easy, but I cannot bear leaving any critical piece of gear behind! Obviously, I don't do any overnight hikes with all that gear - just day hikes.
The reason I now lug all this gear everywhere I go, is that many years ago, I had hiked all the way to the top of the tallest sand dune at the Kelso Dunes in the Mojave desert. It was close to sunset when I got to the top and I had decided not to take any camera gear, since it was tough walking in the dry sand and took a fair bit of effort to reach the top. Well... wouldn't you know it - I witnessed the most spectacular sunset of my life... in my recollection still unequaled to this day!
As a backup camera, I also currently carry the Fuji FinePix S200EXR - previously, I used a Fuji FinePix S100fs or a Canon PowerShot Pro1 as a backup.
I have used the S100fs extensively, and it is a very impressive camera in its own right. With 11 megapixels of resolution, RAW shooting with decent image quality up to ISO 400 and a very high quality 28-400mm image-stabilized zoom, I have actually been known to just shoot with the S100fs in lieu of my Canon SLR gear! Those times where quick changes of focal length are necessary or when I don't want to constantly be slowed down by taking off my backpack and changing lenses, a super high quality P&S digital, like the Fuji, comes in very handy.
One example was on my trip to Oregon back in June of 2004, where I took some photos inside a lighthouse. With all the people crowding around, waiting for the tour, it would have been awkward if not impossible to get the photos I did in the brief time I had with my Canon SLR gear - I just walked in with the Canon Pro1 around my neck and knew that its 28-200mm zoom would cover basically anything I might want to photograph.
Another example was on my recent trip to Hawaii with my father and my aunt. There was so much to photograph that if I had constantly been using my SLR, they would have had to do a lot more waiting! As it was, I frequently used the Fuji S100fs - it was much faster to use since it has such an incredibly versatile lens, but it still allowed me to capture high quality images that are suitable for large prints.