c# concurrent http searches

What I need is a class written in C# that will do the following: An input of multiple urls will be passed to the class in some format (string array, arraylist etc, or even individually) This class will then need to send out the http requests and obtain a string of the html code returned from each http request. The http request must be made asynchronously in some way whether it's threaded or using the asynchronous workings of the IAsyncResult object or however you choose to implement it. This class must be able to handle any amount of URL's and like I mentioned, these must be executed in parallel to improve the performance of the html retrieval. I am looking for the actual code in the end, not just a dll etc. I will be modifying the code afterwards to integrate it into my own current project.