Cost of Living Salary Calculator
Enables you to do a city-by-city comparison of national cost-of-living differences

Salary.com
Very comprehensive site with up-to-date compensation information

JobStar.org
Job search site with an excellent salary/compensation section including links to over 300 salary surveys

Bureau of Labor Statistics

Job Search Compensation Center from About.com
Tips, tools and insights into salary and other compensation

ERI Economic Research Institute: College Students Career Planning
A website with compensation and benefits research. Includes information about expected career earnings, cost of living analysis, expected starting salary survey, and salary assessor tools

America's Career InfoNet
Maintained by the US Dept of Labor this site includes information on over 460 occupations as well as market outlook predictions and job listings

Payscale.com
Provides salary comparisons. Enter your information and generate a personalized report that shows how your salary compares with others.