Thanks again for the explanation!
I remember the smaller the aperture, the less depth of field but I didn't remember what you told about.

About the water resistance, well, I do care about ^^ (that's why the K7 took my attention in the first place) because I prefer taking outdoor pictures with any kind of weather. A week ago, there were some nice weatherlihgts (similar to lightning but it's not like normal lightning followed by a thunderstruck.) Anyway, I could have taken some nice pictures, only if it wasn't raining (not much rain, but too much for the camera). I also like to go in the forest, walking and sometimes hide in the bushes to observe wild animals. And forests are more humid. So it would be ennoying to take out - put away the camera all the time and wipe off the camera every time some water gets on it. But everyone has a prefered domain I guess. So for me, the WR has its importance due to the places I visit, and you never know when some water gets spilled on it by leaves keeping water etc.

Now, I think this topic is coming to an end. I was hesitating between two cameras and finally, I chose a third one.

For the ones who read this topic and can't choose between D5000 or D90, go K7. No, kidding ^^ If I learned the lessons here:

- if you have old lenses or plan to get other lenses than the 'kit' ones soon after your purchase of the camera, go for the D90. You will have larger choice due to the built-in AF motor. And the viewfinder has also more coverage.

- If you plan to stay with the kit lens for a while, have less money and can't live without
a tilt and swivel LCD screen, go for the D5000. (that's the choice my girlfriend made).
She's so used with liveview on P&S that she prefers taking pictures like that (but not me).

I hope this will be helpfull for others out there who have difficulties with choosing.

Now I just have to wait for the next payday, learn how the cam works and I hope I will have some nice pictures to show to you (and get constructive critics on them). I have still a lot to learn and I have the feeling this forum is plenty of experienced users with a lot of knowledge! Thanks to you all and keep shooting!