Here's something from the other side of the career search equation. I am a recruiter and I use LinkedIn quite a bit to find candidates. I like the quality of candidates I find but one thing that frustrates all recruiters is the inability to quickly connect with candidates who are looking for work on LI.
Too many times candidates have their profile locked down. By this I mean only the last initial is shown or the name is marked private. I have to do a some detective work to find their last name. Then more detective work to find a contact email address or phone number.
Remember if you are not working, recruiters can't track you down through your work phone. If you are using LI to find a new job, make sure you have a piece of contact information, preferably a phone number, easily discernible, so we can talk quickly.
Another tip is to load up your profile with keywords relevant to your skill set. I would list as much as you can especially jargon words related to your industry.
Do yourself a favor, if you are looking for work and using LI, make yourself easy to find and easy to contact. It will significantly improve your chances of being found.