Starting around 10 am, there were intermittent outages reported by users. For some, the site was not rendering or slow, while others were unable to post updates. Richi Jennings, visiting San Francisco, was briefly unable to reach Twitter.com. "Not even a fail whale," he told The Standard.

This was the first major outage for Twitter in many months. In early 2008, the company was prompted to expand the service's technology infrastructure and staffing after hours-long outages at Macworld and other events. -- last month, Twitter's Pingdom report claimed 100% uptime for December, and the 2009 Macworld event two weeks ago did not bring down the service.

However, today is different -- the sheer number of people tweeting from the ground in Washington D.C. and their homes as they watch inauguration coverage on television is unprecedented.

Tuesday, the Twitter Status Blog , and said the company was working on the problem.