Heres a weird one for a Friday arvo...

As of Wednesday night, I've no longer been able to access Twitter on my iPhone. Attempts to refresh kept timing out. This was with the Twitter client app, but I also have the same problem with TweetDeck, and pointing Safari to http://mobile.twitter.com, or http://twitter.com. 

I have tried removing my account from Twitter (and TweetDeck), but it now times out during the authentication step of adding them back in again. I've even removed access permission for the Twitter and TweetDeck apps from http://twitter.com/settings/connections, but that made no difference.

I've had some problems with TweetDeck on my desktop (OSX Snow Leopard) over the last few days, but these are relatively infrequent and recoverable (and only seem slightly more than usual, so probably a red herring).

I tried using the Twitter client on my wifes phone (also an iPhone 4), and she is experiencing the same timeout issue. And I just tried http://mobile.twitter.com on my desktop, and that worked perfectly.

Any suggestions gratefully received.

Edit: Forgot to mention that other apps (e.g Facebook) and web pages are working without issue, so its unlikely to be an Internet connectivity issue.