With about 1,400 employees in Palo Alto, Facebook expects to grow its workforce by about 50 percent this year. Previously, the company announced plans to expand into the former Sun Microsystems campus in Menlo Park, a complex of nine buildings that can house roughly 3,600 workers. Facebook Plans to Boost Its Staff by 50 Percent This YearAt the current rate of growth, Facebook could have about 10,000 employees by 2015. About two thirds of the company's employees work at offices in the Bay Area. Facebook executives have said they plan to recruit locally near the former Sun campus, which is situated at the Western end of the Dumbarton Bridge not far from East Palo Alto. The company says it will have a special recruiter dedicated to helping Menlo Park residents find jobs with the social networking giant. -- Doug Bartholomew