When you're reading that latest Twitter tweet , did you ever wonder where the author was when he wrote it?

You might be surprised to find out how many tweets are posted when the Twitterer is driving a car, watching a movie or - yes, it's true - when they are in the bathroom.

Crowd Science, an online measurement service, reported today that a little more than one in 10 Twitterers admitted posting to the social network while driving at least once during the last 30 days. Crowd Science said the Twitter result compared to about 5% of other social media users who fessed up to posting while driving.

Meanwhile, 17% of Twitter users confessed to accessing the microblogging site from the bathroom, while 12% of non-Twitter social media users had done the same.

According to Crowd Science, if you're on a date with a Twitter user, don't expect their full attention. Thirty-one percent of Twitterers say they tweet from restaurants, and twice as many Twitterers as non-Twitterers, access the site from a theater during a movie or live performance.

"Twitter is more of a mobile media phenomenon than other social networks, so these results, while a little disturbing, are perhaps not so surprising," said John Martin, CEO of Crowd Science, in a statement. "And even though checking updates outpaces tweeting by almost two to one, the bottom line is that either types of activity take a driver's attention away from the road."

The Crowd Science survey, which was conducted online this past August, also showed that many people are mostly because of peer pressure.

The study showed that 17% of Twitterers say they are reluctant users, but fear that stopping would hurt their social status.

Crowd Science also noted that 32% of Twitter users say they spend too much time using social media, 22% say they've written things on social media that they've later regretted, and 16% report that they often neglect important activities to spend time on social media.