I found an interesting link today while I was surfing the social bookmarking site http://del.icio.us. Basically I found a blog where a developer created a "Programmer Competency Matrix". It basically breaks programming knowledge down into basic groups and levels. Here is an example:

This matrix could serve as an interesting way to rank programmers in an organization or to even figure out compensation rates for your staff. Anyway, to see the full matrix visit the IndianGeek website.