A recent blog post by Joel Spolsky talks about job level and pay scale, and Spolsky said he got some of the idea on uniform salary for a particular job level from Construx.
I went to the Construx website. Construx is a company that provides software-engineering consultancy and advices. I didn't delve deep into its business, but I am quite impressed by the technical ladder this company provides to its employees.
The Construx Professional Ladder provides a very good pointer for software engineer at all type of skill levels. What I find valuable is the reading list.