During my many years as an active volunteer in IEEE standards, the Computer Society, and other groups such as the web consortium, X/Open (The Open Group), XIWT, ANSI Information Infrastructure Panel, etc. And also my limited scholarly work in academia -- I found that active involvement in professional activities yielded significant benefits for both myself and my employer.
Being active means participation, not just being a member/ subscriber. Attend local chapter and section meetings -- initiate your own events in areas of particular interest! Participate in conferences (attend, submit papers, join organizing committees) that are in your area(s) of interest. Join standards working groups, and contribute -- they can always use editorial support even if you don't feel you can make technical contributions. (Trust me, eliminating ambiguous wording is a real contribution in standards, and often folks a few steps away from the topic are more effective.) Participate in events: professional development training, annual outings, judging science fairs, supporting Lego or FIRST robotic teams, teacher in-service training, etc. Join management committees - chapter program board, editorial boards for publications --- respond to that "call for volunteers" -- we really do welcome new faces, new ideas.
Why? -- besides giving back to the profession, you will meet people - connect with colleagues whose fields of interest will overlap yours in useful ways. This is called "networking" - and it only works if you have fairly regular contact in communities such as those above.
Building relationships takes time. It is hard to call someone you have only met once, and then some time ago, to ask that key question. Stay in touch - the easiest way is "being there" at events you have in common, occasional emails are a second tool. Get a sense for what they value and what interests them. Follow up on these things as well -- sharing a pointer to a new article, event, or other resource that is a good match.
Here's what networking can do for you and your employer
Standard Business Cards by Vistaprint
Find your local CS Chapter or Student Branch Chapter at: http://www2.computer.org/portal/web/chapters/prochap