I feel a bit of a cheat with this Thing really, as I already have a Linkedin profile and use it regularly. The benefits are immense; it provides a strong professional network, an alternative to the more social networks. I particularly like the function to join groups and I have learnt a lot from the CILIP discussions.
Sometimes one gets the feeling that, once the network of professionals has been created, no one is really sure what is supposed to happen next. Some people share news articles with their network and others have linked their Twitter feed. As I have mentioned before, I quite like having some things in different places and feel no urge to group everything together.
I think the long term benefits of this tool are more useful than the short term gains; in the current climate, being part of a strong network of professionals with a visible online presence could well make a real difference.