Twitter this time says:
Changes for Some SMS Users—Good and Bad News
Let’s start with the bad news. Beginning today, Twitter is no longer delivering outbound SMS over our UK number. If you have been receiving SMS updates from Twitter via +44 762 480 1423, you’ll notice that they’ve stopped and you may want to explore some of the alternatives we’re suggesting.

Note: Updating via our UK number remains fully supported and these changes do not affect users in Canada, India, or the United States.

Before we go into more detail, here’s the good news. Twitter will be introducing several new, local SMS numbers in countries throughout Europe, in the coming weeks and months. These new numbers will make Twittering more accessible for all the folks who have been using SMS to send long-distance updates through our UK number.

Why Stop Sending SMS To Some Countries?

Mobile operators in most of the world charge users to send updates. When you send one message to Twitter and we send it to ten followers, you aren’t charged ten times—that’s because we’ve been footing the bill. When we launched our free SMS service to the world, we set the clock ticking. As the service grew in popularity, so too would the price.

Our challenge during this window of time was to establish relationships with mobile operators around the world such that our SMS services could become sustainable from a cost perspective. We achieved this goal in Canada, India, and the United States. We can provide full incoming and outgoing SMS service without passing along operator fees in these countries.

We took a risk hoping to bring more nations onboard and more mobile operators around to our way of thinking but we’ve arrived at a point where the responsible thing to do is slow our costs and take a different approach. If you don’t live in Canada, India, or the US, then we recommend receiving your Twitter updates via one of the following methods.

* m.twitter.com works on browser-enabled phones
* m.slandr.net works on browser-enabled phones
* TwitterMail works on email-enabled phones
* Cellity works on java-enabled phones
* TwitterBerry works on BlackBerry brand phones
* Twitterific works on iPhones

Twitter SMS by The Numbers

It pains us to take this measure. However, we need to avoid placing undue burden on our company and our service. Even with a limit of 250 messages received per week, it could cost Twitter about $1,000 per user, per year to send SMS outside of Canada, India, or the US. It makes more sense for us to establish fair billing arrangements with mobile operators than it does to pass these high fees on to our users.

Twitter will continue to negotiate with mobile operators in Europe, Asia, China, Australia, The Americas, and other regions to forge relationships that benefit all our users. Our goal is to provide full, two-way service with Twitter via SMS to every nation in a way that is sustainable from a cost perspective. Talks with mobile companies around the world continue. In the meantime, more local numbers for updating via SMS are on the way. We’ll keep you posted.
http://blog.twitter.com/2008/08/changes-for-some-sms-usersgood-and-bad.html

Photo sharing site Flickr is one of the leading lights of Yahoo – but cofounders (and husband/wife team) Caterina Fake and Stewart Butterfield won’t be around to keep driving the product forward. They are both joining the mass exodus of executives from the company.