nice shots. as to the background defocused (its called shallow depth of field [DOF] and artistically "bokeh") its easier achieved through nice prime lens (like the ones on your camera) and a bigger sensor.
the burst mode on the nex are awesome, but you can get great images from the D40 as well (but it just takes some knowhow. there are some video guides and user guides out there..
sadly ken rockwell has a pretty good guide for the d40.. sadly, because the guy comes off like a huge douche but he does make a great case on why the d40 is a great camera.
http://www.kenrockwell.com/nikon/d40...uide/index.htm
Quote:
Originally Posted by
blofeld 
I never seemed to be able to get a super crisp shot with the S90 (probably because I'm not very good). Also, it was really hard to get shots with the background defocused. The D40 I just never took the time to learn to use well, and the NEX-5's 14+ MP count I think has something to do with it as well. The NEX just seems to shoot images REALLY fast...especially in burst mode which is how I have got every good shot of my son so far...I also like that the NEX saves each image to the card in both JPEG and RAW, and the editing software that came with the camera is easy to use. All in all, I think a pretty sweet deal for $650.