1. Justin Bieber
He’s an absolute sensation on Twitter, with his name often trending in the top 10 Twitter trends. His account is used mostly for outreach to his fans and career promotion, but it’s a useful way to keep in touch for hardcore fans. Sample tweet: so in 1 week…next tuesday…the song I wrote about how how all of u make me feel….. SMILE hits ITUNES

2. Barack Obama
The President of the United States has had an Twitter account seemingly forever, using it actively during campaigning. Or more to the point, his aides were using it actively. His very first real tweet came after the Haitian earthquake as part of a charity appeal. If politics is your bag, this is one to watch. Sample tweet: Speaking about the urgent need for health insurance reform this morning at Arcadia University – watch live at 11:00am ET http://j.mp/dvUmn2

3. Kevin Pollak
This actor tweets a bit of everything and is pretty actively networked in the Twitter community. He can often be found retweeting other celebrities, so his account is a great way to discover other high profile folks. Sample tweet: Fav Fact Tweet of the day: RT @jaime_fox I had to see Capt EO twice today just because it’s so 80s cheesetastic!!!

4. Jared Leto
This actor turned musician is a very active Twitter user, although his tweets are mostly pertinent to his career, especially his experiences with his band. His band, 30 Seconds to Mars, also has a Twitter account. Sample tweet: Haaa Who threw these glasses on stage and whered they go? RT @thisismadeline: http://twitpic.com/178l53 – I love this photo soo much

5. Yoko Ono
The widow of late legend John Lennon tweets mostly words of wisdom, some profound and some rather mystifying, but all of them thoughtful. Sample tweet: Draw a window on the wall to remind you of the fog that covers your worries

6. Neil Patrick Harris
This charismatic actor tweets from the heart with lots of content about his professional life and random thoughts stream-of-consciousness style. Sample tweet: Being asked to open the Oscars – Awesome. Rehearsing and performing – Awesome. Reading some of the vitriolic reaction – Not quite so much.

7. Lindsay Lohan
If you ever wanted to know what day-to-day life was like for…and the inner workings of the mind of…actress Lindsay Lohan, her Twitter account will answer all your questions. Sample tweet: http://twitpic.com/17ju1z – hmmm? what kind of face am i making?! i’m confused? Lol

8. Imogen Heap
This British singer took Twitter to a whole new level when she accepted a Grammy award in a dress actually wired to Twitter, displaying photographs submitted by Twitter-going fans. Sample tweet: Last night’s gig was so special for me. Just managed to hold it together for Hide and seek. Copenhagen… You sang beautifully! Much love x

9. Moby
Musician and activist Moby seems to tweet whatever interests him, professionally or otherwise. Often his tweets contain recommendations or commentaries on hot topics like politics. Sample tweet: “We used to hustle over the border for the health care we received in Canada” – Sarah Palin. again: ah, republicans…the party of comedy.

10. Ashton Kutcher
A very active Twitter user, the often imitated but never duplicated actor is rather difficult to pin down. A blend of photographs, personal tidbits & professional news can all be found in the mix. Fans will likely enjoy the randomness. Sample tweet: Time for a hair cut. I’m starting to look like Justin Beiber http://yfrog.com/4v45ecj

Related: John Mayer & More: Top 10 Celebs to Twitter Stalk [pt 1]

The as-yet fledgling account is mostly being used to post content from his existing web site, but it’s expected that he will tweet more actively. His following jumped overnight from a few hundred to nearly 90,000; it’s only a matter of time before he addresses that audience more personally.

The Dalai Lama is the 14th in a line of Tibetan Buddhist spiritual leaders believed to be reborn to teach and provide spiritual guidance. Thus far his tweets are mostly politics, education, photos and media, such as video of a recent interview with CNN’s Larry King and comments about China. [via Mashable]

Enter PleaseRobMe.com, a web site that displays Foursquare location updates similarly to Twitter. Developers Boy Van Amstel, Frank Groeneveld and Barry Borsboom feel their site draws attention to the security risks posed by such open and frank disclosure of location as Foursquare and mobile micro-blogging provide. But director of Privacy International, Simon Davies, feels differently.

“What they have actually achieved,” Davies said, “is providing a one-stop-shop for burglars rather than achieve their goals, which are to raise awareness.”

PleaseRobMe.com’s mission statement is clearly displayed:

“Our intention is not, and never has been, to have people burglarised. On one end we’re leaving lights on when we’re going on a holiday, and on the other we’re telling everybody on the internet we’re not home.”

Whether or not the concept is effective at promoting awareness or, as Davies argues, is effective only in giving burglar’s tips about empty homes, may remain a matter of personal opinion. [via Ananova]

Nielsen revealed 12% of 2009 Super Bowl viewers also took time during the game to use the web. Surprisingly, of those viewers only 18% visited sports-related sites. The majority spent their time on Facebook, suggesting the importance of social networking during cultural events of such magnitude as the Super Bowl.

If you plan to use the web during this year’s game, keep an eye on #sb44 on Twitter – it may be this year micro-blogging eclipses pure networking in viewer popularity. [Mashable]

Chávez’s response was to brand Twitter a threat to the country’s security, with reports stating he went as far as to declare the micro-blogging site a “tool of terror”. Venezuelan National Assembly deputies have begun the task of tackling “terrorist threats posed by social networks”, likely via regulations. [Mashable]

Processing time, or time line delays, at 11:00am ET was clocked at over 4 minutes for a number of users. This means any news or rumors that circulate on Twitter come with a 4+ minute delay, not an instantaneous sharing of information.

Twitter usage is expected to be especially heavy throughout the day, not only with the unveiling of the Apple Tablet, but with President Obama’s State of the Union address airing tonight. It could be a long and frustrating day for regular Twitter users, particularly those who tweet with little to no interest in either topic.

It’s not the first time an Apple subject has slowed down Twitter. In its early days, Twitter was crashed by buzz surrounding a keynote speech that Steve Jobs delivered at Macworld. [via Mashable]

Chief among their protest tools will be…Twitter.

Church members have planned what appears to be a massively convoluted and confusing protest simultaneously against and for the wildly popular micro-blogging site. They will gather between 4:30 and 5:00pm local time outside the Twitter headquarters in San Francisco.

The official line from the church about why they’re protesting Twitter appears to simply be because they can. At the same time, they’re also protesting plans by the Obama administration to restrict freedom of speech via methods like Twitter, and will themselves be tweeting from their anti-Twitter picket lines.

If it’s making your head spin, try reading the statement from the church’s web site. “Now that should get interesting, WBC member(s) Tweeting as they picket outside Twitter, Inc. Won’t a black hole or something open in the space/time vortex? Seriously, let us focus in on a few facts, to wit: Twitter is a company which lends itself to mass communication. Why in heaven’s name would the great publishers at WBC NOT picket this place?”

On the pro-Twitter side, the church site states, “Obama’s about to take away any/all resources like Twitter to serve him and his Antichristic agenda, so enjoy this freedom while it lasts a little longer. Praise God! AMEN!”

If you can make any sense of this protest whatsoever, please leave a comment and help the rest of us figure it out!