Amazon rankings error spurs outrage voiced through Twitter. Amazon's non-specific explanation encourages conspiracy theorists.

And if you are one of the millions who don't quite understand what Twitter is all about here's a hint: it's all about the collective brain and pairing technologies.

Pairing sensors with Twitter leads some to think Twitter could be used to send home security alerts or tell doctors when a patient's blood sugar or heart rate climbs too high. In the aggregate, such real-time data streams could aid medical researchers.

Already doctors use Twitter to ask for help and share information about procedures. At Henry Ford Hospital in Detroit, surgeons and residents twittered throughout a recent operation to remove a brain tumor from a 47-year-old man who has seizures.