With more Americans out of work, career development web sites have seen a surge in traffic, according to a new report from Nielsen Online.  In January 2009, there were 49.7 million unique visitors to these sites, up from 41.5 million unique visitors in January 2008, an increase of 20 percent.
CareerBuilder Network was the top destination with 20.8 million visitors, followed by Yahoo! HotJobs and Monster, with 11.7 million and 9.5 million unique visitors, respectively.  Among age groups, the number of unique visitors to career development web sites age 65 and …