As I have been making my rounds reading stuff at various sites that I visit on a daily basis, I found an excellent slide presentation on social media. I think I have actually seen this one before, but I lost the name and the link of it after I saw it. Although it takes more of a marketing perspective on social media and networking, I think a lot of the information is relevant and translates rather well to career topics related to social networking. I have posted the link to the slide presentation on SlideShare here. While a great presentation, it may not be the safest for work, as she sprinkles four-letter-words throughout the presentation.
James
James Van's Career Blog 
Social media are the best resource to get live updates, happenings in industry. Also you can make career in this field and can come up with some very good opportunities in this field.
SaveMySystem-I agree, that social media is a much quicker way to get information out to the masses. I read an article recently about how traditional media lags behind social media when it comes to developing stories. It can also get eyewitness reports out much quicker too. The drawback will always be the accuracy. Traditional media has processes in place that should check for accuracy. (minus the NYT scandal a few years back) Traditional media often includes more investigative reporting as well.