His latest project, TweetPsych for lists, is an enlightening and often amusing look at what your lists are talking about, how they view the world, what turns them on (or off), and more. Depending on how you group your Twitter friends, you can make interesting generalizations or conjectures about society as a whole. What do the denizens of L.A. or San Francisco tweet about most? What about women - what's got them buzzing? Read on for more on precisely that cross-section of the Twittersphere.

And my lengthy list of San Francisco/Bay Area people on Twitter gave evidence of a complete lack of interest in celebrities and a preoccupation with self, the future and control.

But when I looked at my "Southern Comfort" list of geeks south of the Mason-Dixon line, I got a very different picture. These folks are using the social web to tweet about their emotions, the passage of time, themselves, and dreams of unconscious thoughts, while they tweet less than others about celebrities, sex and money.

When I looked at results for the list of women I follow, I saw they tweet a lot about sex, themselves, the past, anxiety and negative emotions, in that order. It was like watching an episode of Sex and the City flash before my eyes. They tweeted very little about money, learning, control (including self-control) and constructive behavior. Keep in mind, this isn't a generalization about the state of womanhood on the Internet; I follow a very limited and eclectic group of ladies, all of whom I find very charming in their own fashion.

Of course, I had to check out the stats on the ReadWriteWeb crew. We seem to tweet a lot about leisure and activities other than work. Uh, don't tell the boss? However, tweets about work finished a close third, right behind tweets about ourselves. As a group, we don't tend to tweet about personal things, such as money, sex or emotions.

Other interesting hypotheses can be drawn when examining "social media" and "technology" lists. Many geek-centric lists I examined were shockingly devoid of tweets about leisure, positive or other emotions or physical sensations and dominated by tweets about learning, the self and control. Perhaps this is due to our realization that the personal and professional are quickly merging and our perceived need to present a reasonably consistent face and least objectionable programming-type content.

At any rate, Zarrella's given us another insightful peek into how Twitter reveals interesting snippets of information about various demographics and sociological segments.

Give the new lists function a spin, and let us know your findings in the comments!

Dr. TweetDreams pulls together elements new and old, including symbolic meanings from a 100-year-old dream dictionary and any and all tweets containing the phrase "had a dream." "I finally got to use all my cool natural language code," Zarrella told us last night. "I'm using a part-of-speech tagger, a wordstemmer, and Princeton's WordNet to generate a list of related word stems which are then matched against a dream dictionary."

Some of the analyses we tried out were pretty clear-cut:

Other tweets produced hilarious, convoluted or just plain strange results. One of the particularly interesting things about taking definitions from a 100-year-old dream dictionary is the charmingly antiquated social mores; woe to the married woman who dreams of hugging a man other than her husband! And check out the wonderful fortune in store for this lucky young lady:

Ah, how we long for the golden days of yesteryear, when marriage was a woman's best occupation! There were also a few misfires in terms of vocabulary; for example, a hundred years ago, a plane was a carpenter's tool, not a mode of transportation. Nevertheless, we found these idiosyncrasies charming.

Users can take a look at one of the most recent dream-related tweets or check out various analyses on Twitter.

There are Twitter Terms of Service that help dictate how content is shared, and there are generally accepted community guidelines for attribution. Zarrella shared his researched insights on how to get more retweets and leverage Twitter to increase mindshare and drive traffic. He also talked about the value of Twitter as compared to other social networks in terms of conversion.

Zarella said people love to retweet new blog posts from users they follow. They also love retweeting content containing links and don't mind being asked for a retweet. Finally, retweets have a snowball effect; a retweeted tweet is more likely to be retweeted again by other users.

If I never type "retweet" again, it will be too soon.

Check out Zarrella's presentation below: