Even after changing jobs twice, and seeing my salary increase to a level I was happy with, it became apparent that I still wasn't working with a full deck of cheat sheets. No sooner was the ink dry on one contract but I inadvertently learned from the HR manager that I had signed below the range they expected to fill the position, and the range extended a full $30k higher. Before even finishing my first week at the new job, I knew I had undersold myself once again.
As years have passed, the tools available to job seekers have dramatically ballooned, with professional networking sites like LinkedIn, focused job services like MktgLadder (for those of the marketing persuasion), Salary.com, to give the range of salaries for those with similar titles in your zip code, and now, an open search engine from indeed.com that without requiring any paid subscription, returns average salaries for titles and City/State combos.
Now, instead of walking in with a 2-page resume and hope, you can walk into an interview with a 2-page resume, a host of online references and a raft of business connections, and a very precise expectation of what you'll be asking for - based as much on the salaries of your peers as your previous history. Makes the potential for being laid off in a Valley where nothing is guaranteed seem that much less scary.