Website screenshot capture with ASP.NET and PHP

Capturing the thumbnail of a website is pretty useful when you are creating a web application like web 2.0 directory, site review, website preview, etc... So how do you implement it in your language? I did it in my asp.net application which was was very easy. And i searched for the way in PHP. Although, PHP doesn't support natively, there are tricks that you can use to capture screenshots of websites. Here is the code snippets;