如何从像Digg提交按钮的URL中获取其他网站信息？

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.I'm creating a website using the cakePHP framew