Ok.. this is going to be a long post
I'm wondering if a nikon d40 has so much more control over pictures as opposed to something like this
Well, in a nut shell, yes it will offer more control.. but there's really more to it that just the simple question. A DSLR like the D40 (or the Canon XS near that price range) is significantly different than a Point & Shoot like the others you linked to.
From a "control" perspective, the most obvious difference between the P&S and the DSLR is the ability to use multiple lenses which provide not only different zoom/focal length but also different aperture ranges.
You also open the world of accessories with different flash options and filter options not usually available to P&S cameras. A DSLR, you view the image through the lens.. what you see is what the lens sees - this is not the case with a P&S by design. From the not so obvious perspective, you have much better control over exposure and, if you choose to shoot in RAW mode, much better control when doing post processing.
Depth of Field - something almost every P&S lacks is the ability to produce a nice shot with the ability to adjust the depth of field in the final picture. With the variety of lenses/zoom lengths/aperture, you can can adjust yoru picture to give a nice blurred background or not depending on your needs and wants for the shot.
Camera Startup, focus speed, "shutter lag" are all usually much better in a DSLR. I can take my Canon XSi, turn it on and take 3 pictures in burst mode in under a second (time to first picture is usually about 0.25 seconds if the lighting is good. Try that with a P&S..
While the P&S may have manual mode settings, they are geared and designed with the assumption that 90% of the time, the user is shooting in some pre-programmed/auto mode. Changing/adjusting the manual controls can be difficult at times. A DLSR is generally designed with the assumption that 90% of the time, the user will be shooting in a mostly manual way and the controls are generally fairly easy to access and set. You can change ISO, shutter speed, aperture, exposure compensation, focus point, flash compensation, etc without removing your eye from the view finder.
Image quality - DSLR use larger sensors. Larger sensor = lower noise = better picture quality (especially at the higher ISO range and higher shutter speeds). No contest here.
Because you are able to change lenses, the lenses generally move with you (assuming you stay with the same brand/line). Your investment is in the glass more than the body allowing you to upgrade to better/newer models with more features/control/etc
Again with the lenses, but you can get much more quality glass for a DSLR then you can ever find in a P&S camera.
Of course, there are some cons to a DSLR..
1) Price - they cost more and you may want to buy different lenses, accesories, etc
2) Size/Weight - they are bigger - both the body and the lens. You usually end up with more than one lens - meaning bigger bags more stuff to haul around.
3) Requires some maintenance - adding/changing lenses and parts means the risk of dust etc getting into your camera..
4) Physical noise - generally the motorized autofocus and the mirror going up and down produce a noticiable "clunk" when taking pictures as opposed to a P&S that has no moving parts when taking a picture. Well, I like the auditory feedback, but not everyone does.
5) Learning - all these things require learning and practice. Most of the time, my first pictures were crap - I took much better pictures with a P&S than with the DSLR - again - mostly because of all the options for "control" that you have and the dumbing down of the P&S interfaces.
6) No Video (well, the new Nikon has the ability to do video, but it hasn't really made it's way to the lower end DSLR lines that I'm aware of yet.
note: I'm not knocking P&S by any means.. generally, if I'm going to go anywhere worth taking pictures, we'll usually have two cameras - a P&S and a DSLR.. there are just times where the conveience of a P&S can't be beat.
I'm sure there are some Camera Freaks out there that could help me choose a good one but not break the bank for a couple of amateur photogs...
Ahh.. there's the real question is what is your budget?
If you want to go with a lower end DSLR, I would look at the
D40 as you already mentioned or the
Canon XS for a little more.
My own personal preference leans toward Canon - but the Nikon is a nice camera as well. Really, you won't go wrong with either choice. Again, with a DSLR, your real investment is in the glass (lenses). The body can be changed.. and you can move up to a D80 in time (or a 40/50D in the Canon side)
edit: waits for mlakrid to chime in
