For all you corporate types out there, the ones cut off from IMs and online communities, here're a couple of links you may find helpful. Feel free to use the arguments with your bosses and your IT people:
http://discussionleader.hbsp.com/davenport/2007/11/enterprise_20_versus_the_estab.html
http://conversationstarter.hbsp.com/2007/11/the_business_value_of_social_n.html
Happy networking!