I find nature photography to be a particularly equipment challenged pursuit. No matter how much I have, I always find a reason to want more. I'm not sure if this driven from real need or whether it is just an excuse for not taking responsibility for the results. That way I can always claim 'Well, it would have been a much better shot if I had a blah blah blah'. Either way I seem to possess and incredible drive to acquire more equipment. Right now, I'm sure my want list exceeds the list of stuff I already have. >
Over the last few years I have developed a fairly good system for lugging my equipment around with me. If I am hiking or traveling by air alone I will take my LowePro Pro-Trekker with it's usual loading. I consider this to be my main pack and can partake in most of the photographic disciplines I enjoy out of this selection of equipment. The pack itself has been modified to be able to remove the harness so that it will fit with a full load into the airline baggage checkers.
If I am lucky enough to have a companion I will also take my secondary pack. This adds a considerable amount of capability for macro and low light work. This Nature-Trekker is a great little pack with a wonderful harness that makes carrying a heavy load easy and comfortable.
While most of my work is done with 35mm, I use a small medium format kit for the bulk of the scenic images I shoot. The Mamiya 645E in this kit is new to me, but I am growing to love it and take it with me whenever I can. It is the smallest and lightest 6x4.5 SLR I could find and a real bargain. I used to shoot a Pentax 67 and while it was a wonderful system, the weight of the body and a couple of lenses was a bit too much. When combined with my main pack, it made hiking a genuine pain in the back.
When I travel by car I take everything with me including my Pelican case, just in case I rent a boat or bring my canoe. I load this up with equipment that I find is generally more moisture resistant and physically a bit tougher.
To keep all this equipment steady I utilize series of Manfrotto supports. While well made generally a pleasure to use I find there could be some improvements to this system. I am currently looking to change two things in particular. First, the 298 ball head. While it is very stable, it is also very heavy and fairly crude. Second, the quick release. The Manfrotto hex plates a too big and fussy to attach. I have had equipment fall to it's death twice because the clamping cam let go. When I get rich and famous, I will likely switch to Arca-Swiss heads and releases.
Being the equipment junkie I am and never wanting to be caught out for a way to bring the right stuff with me I also employ various other bags. Using these, the packs mentioned above and a photo vest from Misty Mountain I can carry just about any combination of my equipment to just about any location and be prepared for just about any subject I've been able to think of. So far.....