Most are spending more time on social networking sites and less money on job boards like CareerBuilder and Monster, according to a recent survey by Jobvite, a recruiting software provider.

Of the 440 HR pros who responded, 72% said their company will invest more in recruiting through social networks this year. Meanwhile, more than half expect to spend less on job boards.

What online tools are getting the most use? The most popular social networks for recruiters and HR pros:

• Linkedin (used by 80% of those who responded)
• Twitter (42%)
• Facebook (36%)
• Jobster (17%)
• Myspace (13%).

Other traditional, low-cost methods are getting more attention in this economy as well — for example, 68% of companies said they plan to increase the use of employee referrals.