URL123 is a casualty
URL123 is (or was) a service written by friend Francesco that made it really easy to shorten URL's. No, it's not a unique service but I've always used it and the toolbar button has allowed me easily share nasty URL's from MSDN or Amazon. I wrote about URL123 back in June last year.
And now it's gone, another victim of spammers 
Unfortunately, over the past 6 months, the use of URL123 as a spamming tool has risen exponentially. Spammers have been using and abusing the system to create links to SPAM pages and ads. This is not appropriate use of the URL123 service. URL123 was created as a way to share shortened links with friends, not to be used as a spamming tool.
Due to increasing daily complaints from SpamCop, GoDaddy, our ISP, and in response to hundreds of SPAM complaints every week, I have no choice but to shut down the URL123 service temporarily until I am able to work on the code and turn it into a paid service. The URL123 service will shut down on September 10, 2006. 
Being considerate, Francesco has let existing links work. So my earlier link to http://url123.com/y8q4s still links to (and considerably shortens!) the C# docs on MSDN. I'm hoping this remains true.