Three surveys of librarian salaries have been recently published.
The Association of Research Libraries has published the ARL Annual Salary Survey 2006-07. PDF and Excel versions are freely available.
ALA has published the 2007 editions of the ALA-APA Salary Survey: Librarian—Public and Academic and the ALA-APA Salary Survey: Non-MLS—Public and Academic. Various priced access options are available.
Here's an excerpt from the ALA press release:
Analysis of data from more than 800 public and academic libraries showed the mean salary for librarians with ALA-accredited Master’s Degrees increased 2.8 percent from 2006, up $1,550 to $57,809. The median ALA MLS salary was $53,000. Salaries ranged from $22,048 to $225,000.
For the first time the non-MLS salary survey data, including 62 non-MLS positions, reported salaries for staff employed as librarians but who do not have ALA-accredited Master’s Degrees in Library Science. Non-MLS salaries ranged $10,712 to $143,700.