Twitter, which has been more reliable than Facebook in the last year (after years of frequent outages), is down / offline worldwide this morning. As of this blog post (at 9:43 a.m. Tucson / Pacific time), it has been down about 30 minutes.
A bit of research indicates that Twitter engineers are working on the problem but there has been no indication as to how long they estimate it will be down.
I'm suffering withdrawals. It isn't as fun to Facebook in the bathroom as it is to Tweet.
UPDATE: It came back just about 10:30 a.m. and has worked fine all day since then. Three cheers for the Twitter engineers for getting it fixed fast! The cause was two data centers that failed simultaneously. Normally they can switch to a second one if the first has a fail and two took a dump at the same time.