A good tripod ($100-200 minimum) is a must. I have a Bogen 190 xb with a 322 grip style head with RC 2 quick release plate. I also hot the Bogen L bracket that accepts the RC 2 plates for shooting verticals for panoramics. Very nice stuff that doesnt break the bank. Got is all from B&H. Don't cheap out on the tripod if it can be helped.
I got a Hoya Pro 1 UV (and CP) for my 24-105 and 100-400. They are awesome. I can use the CP on my 10-22 after about 13-14 mm without too much banding in the sky. As a bonus, it has front threads to accept my lens cap. Most CP's don't. It is a slim CP and works great on all but the widest focal lengths. Even then, it would be great as long as you don't have a baby blue sky. The UV was perhaps $80 or so (for the 77 mm) but worth every dime. I can see no image degradation since putting them on. Check out the below site for great prices on filters. I wish I had heard of them before I bought mine. My UV and CP cost much more at B&H than this site sells them for. I think my $190 CP (from B&H) is about $110 on the below site. Lessons learned.
http://www.2filter.com/
The battery that comes with the 40D will get you AT LEAST 400-500 images. I would hold off on the battery grip for now. Some have complained about it when using on a tripod and overall fit. Buying an extra battery is always a good idea, but be aware that the Li-ion battery that comes with the camera has a very long life.
I have also heard that the benefit of the 50 f/1.4 is very marginal compared to the 50 f/1.8, yet there is a signifcant price difference. Your needs will dictate if it is worth it to you, but I would research some old post before spending so much extra on the 50 f/1.4. Below are two such threads (of many).
http://photo.net …a-fetch-msg?msg_id=00PV3J
http://photo.net …a-fetch-msg?msg_id=00PV9I
The remote shutter release is a great idea. I have got lots of use out of my Canon RS-80N3 and it was only $35. Great to have for sure.
Get high quality cleaning kit. I got a Giottos kit that had a retractable brush, blower, etc.. for about $20 at B&H. Some high quality microfiber cloths should be added as the one that comes with the kit is cheap.
I get lots of use from my Hoya Pro 1 DMC CP. Depends on your needs of course, but if getting a CP, this one is great. I find the CP to be the most used filter for most people. I also got a 3 stop soft grad ND from Singh Ray. It is the Galen Rowell model and works great when the sky is bright and I want to keep some detail in the foreground. I am just learning how to use it as I got it about two weeks ago, but thought it would be worth mentioning if landscape photography is of interest to you. Below is a link to a picture here on Nantucket I took about two weeks ago. One is a RAW image right out of the camera, the second is with the grad nd and some mild pp in Photoshop Elements 6.0. PSE 6.0 is great by the way and only cost about $90. On the below link, click slideshow (in the upper right) and see the difference in the two images. Toggle back and forth with the arrows. I have lots to learn, but the below image will show what a grad nd can do.
http://www.flickr.com …2/sets/72157604922316549/
I have a Lowepro backpack that I like. Many others out there of course, but Lowepro has a great selection of camera bags/backpacks to choose from. On B&H I think there are about 60 Lowepro bags. Go to Digital Photography-bags-backpacks-lowepro. Nice stuff. They have the only waterproof bag I can find, the Lowepro Dryzone. If you are a nature photographer, you may want to take a look.
A bit of a luxury item I just got a few days ago is the Epson p-3000. It will hold 40 GB of images and has a tack sharp 4" screen that you can view them on as well, showing all exif data and histogram. You can zoom in (even on RAW images) to ensure a sharp capture was made. This is a great way to back up the CF cards while on trips, but also allows you to delete the obvious trash images and cut down what you put on the PC upon returning home. I am going to Alaska Thursday and thought this would make a great accessory. I will look forward to viewing the images in the motel room at night, or during lunch, etc.. If I don't like what I see, I can go back and try it again with different camera settings. The Epson downloads fast too. I put about 200 RAW images into it from a CF in about 3.5-4 minutes. I was impressed. Very easy to use too. Take a look here.
http://www.bhphotovideo.com …media_Storage_Viewer.html
Canon 5D Mark II & 50D with 17-40, 24-105, 100-400, 50 f/1.4, 100 f/2.8 macro, and 1.4TC
FEISOL CT-3442 (ARL) tripod w/ Photo Clam 40-NS ballhead