So I decided to buy a DSLR... But which? Price range is to 800$.
In this range we can find Canon EOS400D, Nikon D40, Nikon D70s...

So I need a help to make my decision...
If you have a experience of one of those cameras and can tell me about them!

P.S. I do travel a lot and I love hiking... so my choice must be based on this.

Well... first thing is read the other threads on DSLR... after you've done that, you need to do math... on weight of items

Examples:
N-D70s = 679g/24oz
N-D40 = 522g/1.2lb
E-400D = 556g/19.6oz

On top of this you will need to factor in:
- weight of batteries
- lens weights (or how many lenses you are travelling with - a kit lens will weigh a lot less than a expensive L/VR series lens, but may not have the quality)
- Grips - good hand grip might be an idea especially if you're handholding the camera
- Casing (a good camera backpack)

And if you're as unforgiving to your equipment like i am... some insurance would be an idea too.

Don't belive the megapixel hype... go to a shop and try a few camera in the field. The Nikon D40 is a bit too basic for my liking (with the lack of drive for older nikon lenses) but makes up for it on cost and that with a smaller sensor, you can squeeze more pictures per card on. The EOS is more expensive, but has dust cleaning, a larger sensor (so good for cropping, not for your CF cards)

Good luck!

If you are considering the D40 or the D70s, you may want to take a look at the D40X which is either just coming out or to be out shortly. It has a slightly newer sensor and is 10MP over the other 6mp models.

For beginning, the camera will have everything you need to get started and still have plenty of room to grow. I took the D50 over the D40 only because of the fact that I was coming from a N80 film camera, and all my gear worked on the D50, and it's almost the digital version of the N80. Besides, I couldn't afford the D80.

If you have no money tied up in lenses already, then it will be easy to go forward with more modern lenses. If you had older lenses, I would not recommend the D40 line because they are not compatible with the older lenses...but the D50 and D70s are/were. I would take the leftover $$ and buy a nice lens, a very popular and affordable one is the 50mm f1.8.

Also note, the D50, D70, D70s, and soon the D40, are out of production. Right now it's the D40 (to be D40x) and the D80, then it goes to the Pro line from there.

try other slr like sony or olympus...they are also as good as nikon and canon...

Consider Pentax, they are gooood