Social Media

I'm curious on other real estate agent's opinion on social media. Are many agents using it and if so, are you seeing results? I am currently on Twitter and I have a fan page on Facebook. I also have an account on Linked In. People say social media is the next big thing so I do think it's important to create a presence in these places but I haven't really seen any tangible results as of yet. I often use these medias to post links to my blog, so I do see the increase in traffic to my site, but I have not seen any leads created from any of these medias. I would be interested to hear other stories from agents who may have had some success from these mediums. Do you think they are here to stay or just a passing phase? How important is it to clients to have their agents up to date on these things?