Message Boards: Connect with Clients and Agents
RealTown Communities – Forums, groups, blogging, and more in this free online community
http://www.realtown.com/community/

ActiveRain – Connect with other agents and build your referral network
http://www.activerain.com

Trulia Voices -  Post and answer consumer and agent questions at this free forum
http://www.trulia.com/voices/

Zillow Discussion – Another trafficked location to respond directly to consumers
http://www.zillow.com/forum/site

Social Network Websites
Facebook – Connect with clients, agents, friends and more at the largest social network website
http://www.facebook.com

Myspace – Still the king of social networks in the US for connecting online
http://www.myspace.com

LinkedIn – Social network site focused on business relationships and industry knowledge
http://www.linkedin.com

Ning – Use this site's free tools to build your own social network
http://www.ning.com

Blogging Tools
Wordpress – The most popular blogging platform with tons of easy, free plug-ins
http://www.wordpress.com

Realtor.com – Get a free blog here and, with luck, get your post on the “Let's Talk” homepage
http://talk.realtor.com

Blogger – Google's free blogging platform. Another fine choice.
http://www.blogger.com

Twitter – The go-to site for “microblogging” posts from your cell phone and more.
http://www.twitter.com

Useful Tools
FeedDemon – Use the power of RSS feeds to stay on top of your network and the news
http://www.feeddemon.com

Drop.io – Easy, secure file sharing from your phone, fax, email, and even your website or blog
http://drop.io/

Pidgin – Program that can instant message with AIM, Yahoo, Gtalk, MSN and more, at the same time
http://www.pidgin.im/

AddThis – Embed this free widget in your website or blog to share the page with many social networks
http://addthis.com/