After 25.000+ shutter actuations on my D40, I got a D90! So far it seems like a huge leap forward for me. The image quality seems to be comparable, if you count out the increased resolution. But the major improvement lies in the controls and the handling, which is outstanding compared to D40:-)
I'm a 30 year old guy living in Oslo, Norway. My photographic interest really started after buying a cheap SLR on a vacation in 2006 - it opened a new world to me!
Check out my photostream at Flickr: http://www.flickr.com/photos/sverrelerre/