I entirely agree with Andy's original idea - build your network before you need it. It helps enormously when you need to change. Out of the blue in September 2010 the government decided to abolish the organisation I worked for, and having a Linked In network has been extremely helpful in finding work. All the agencies use it to back up what it says on your CV. More details here:

http://dbatasks.blogspot.com/2010/12/social-networks-for-dba.html