As many of you have discovered by now, jquery.com and its subdomains have been offline intermittently over the past several weeks. On behalf of the jQuery Project Team, I apologize for any inconvenience this has caused.
John Resig is aware of the problem and is working with the hosting company to get things resolved as quickly as possible. In the meantime, Remy Sharp, who runs jQuery for Designers, has graciously provided a few alternatives for API documentation:
He also has the raw XML file of the jQuery documentation in an SVN repository hosted at googlecode.com.
Many thanks to Remy and Jörn for these great resources.