The company I am currently with is very pro LinkedIn and Twitter. Unfortunately Facebook is blocked because of problems that occurred early on with individuals taking advantage of the service and not being smart on what they clicked on. There are a very select few that have access to Facebook and those individuals are on Macs….
In regards to the question: LinkedIn has been very helpful to me as I have advanced my career over the years. I was an early adopter of LinkedIn when I was living up in Michigan back in 2002. I made the mistake then of linking to my corporate email and when I left the company I had to abandon that account because I forgot the password. Since that time as a “LinkedIn Open Networker (LION)” I have built a contact list of just under 700 people and continue to strive connect with professionals that I work with. LinkedIn is a tool and like any tool it can be used to help build your a career or help to destroy it. It all depends on you and how you build your “brand.” Unless your place of business completely bans you from having a LinkedIn profile, you can still build your profile away from the office and access it on your personal smart phone or home computer!