Twitter has announced its '@anywhere' platform for websites,which allows site visitors to Tweet and follow from sites including Digg, Amazon and eBay. Check out the video at the bottom of the page.

Speaking at a keynote at SXSWi 2010 Twitter CEO Evan Williams explained how the new "highly anticipated" app platform would integrate Twitter into websites, so you could follow and tweet without having to go to Twitter itself. You will also be able to use Twitter to sign into the site.

Initially @anywhere will be implemented by sites including Amazon, AdAge, Bing, Citysearch, Digg, eBay, The Huffington Post, Meebo, MSNBC.com, The New York Times, Salesforce.com, Yahoo!, and YouTube.

Twitter promises that @anywhere will be simple for site owners to implement as rather than using APIs, site owners need only "drop in a few lines of JavaScript."

Williams said that there were "no real rules" about how site owners should use the frameworks and they were leaving it to developers to decide. "There's a lot that can be done with this that we can't anticipate," he said.

Twitter is certainly excited about the frameworks, saying in a blog post "Imagine being able to follow a New York Times journalist directly from her byline, tweet about a video without leaving YouTube, and discover new Twitter accounts while visiting the Yahoo home page."