LinkedIn is where you, if you work in IT, can broadcast that you're looking for work. It depends on you, your skillset and networking abilities, but it's still pretty good at getting you interviews and recommendations.

The entertaining part, for me, is seeing social media or sales people trying to get a job via LinkedIn. For IT, replies are normally: "I'll call you", tagging someone who is actively hiring or "Reach out to so-and-so at company X, tell them I said hi.". For people who should be experts in sales and social media the replys are "To bad we're not hiring right now", "Best of luck" or "Shared".

10 years ago my biz dev and I used LinkedIn for sales prospecting and it was enormously effective for finding leads to put into the top of the funnel.