Twitter's down like a cheap hooker on a $5 trick during a recession.
http://mashable.com/2009/08/06/twitter-down/ No reason has been noted.
I, personally, think there's a DOS attack going on somewhere - took me a while to log into LJ, FB is having issues and Twitter is totally offline for at least the last hour.
It's the great "Social Media Crash Of Ought 9"
;)
nex