This Forbes video has some good tips for job seekers on how to catch a recruiter’s attention at Facebook, Twitter and other social sites.
First, don’t be shy and change the status of your LinkedIn profile so that your connections know that you are looking for work. Second, get recommendations because lot of companies simply ignore candidates that don’t have recommendations.
Next focus on keywords so that your resume pops up in relevant LinkedIn searches. Some recruiters also look for words like "innovation", "creativity", "work ethic", etc. in resumes.
And finally, do check your "Who’s viewed my profile" page regularly to know if your profile is appearing in search results. If not, it may be time to tweak your resume with some keywords that recruiters may be searching for.
See some more LinkedIn tips.