If you are at all interested in marketing and in a professional service firm, then you probably should join PM Forum (http://www.pmforum.co.uk). The magazine and networking events alone are worth the membership.
Whilst perusing the Summer 2006 magazine I saw an advert in the back for Parallel Mind who coach senior people in professional firms. In looking at their site they have a lovely little promo video about "networking". Follow the link on this page to have a look at the video.
Great little promo video on networking