Yesterday's Twitter outage, it seems, was the result of one blogger, a separatist in the Republic of Georgia. According to CNET:

"The blogger, who uses the account name 'Cyxymu,' (the name of a town in the Republic of Georgia) had accounts on all of the different sites that were attacked at the same time, Max Kelly, chief security officer at Facebook, told CNET News. 'It was a simultaneous attack across a number of properties targeting him to keep his voice from being heard,' Kelly said. 'We're actively investigating the source of the attacks and we hope to be able to find out the individuals involved in the back end and to take action against them if we can.'

Cyxymu's LiveJournal page was also targeted. And Twitter, much to the world's relief, was back up and running fine later yesterday afternoon.