*UPDATE* from @Twitter: "Due to defense measures some Twitter clients are unable to communicate with our API, and many users are unable to tweet via SMS."
Time to hit the bomb shelters :-) - Todd Hoff
Including, apparently, their own web one from some browsers. - John
twitter search has also been a bit spotty. - Joshua Schnell
search is way off, super behind too - Susan Beebe
FWIW: I'm seeing most posts go straigh through to search. I'm viewing search on search.twitter, FF search, Tweetdeck, and PeopleBrowsr (search.peoplebrowsr.com). I'm seeing more lag than usual, but less than 10 minutes in most cases. The odd tweet may take several hours though. - guruvan (Rob Nelson)
Twitterberry seems to be disabled, SocialScope is intermittent at best...guess I need to give UberTwitter another go. - Jared Smith