How do I fetch another websites info from a URL like Digg's submit button?

[Jamesmaps]

I'm creating a website using the cakePHP framework and I and a newbie to php and web programming. I want to do something similar to Digg's submit button, where you type a url and it fetches an image, title and sometimes a short description of the article on the webpage. I'm assuming this would be done using php but I'm open to any method.