I'm not sure how many here have done this, but I just ran an EXIF data survey on 2500+ images, and found that my photos were shot at an average focal length of 72mm. (115mm w/ 1.6 crop). It was kind of interesting to see where I spend most of my time shooting. Analyzing my photos this way is a good way to guide future lens choices. I'm probably going to put off buying the 10-22mm anytime soon since it will most likely end up collecting dust.
**I deleted the results of images taken with P&S cameras and only included the images from the D30 and 20D.