I am using ASP.NET.
There is a system that needs to POST data to my site and all they asked for is for me to provide them with a URL. So I gave them my URL http://ww
The data from the request (content, inputs, files, querystring values) is all on this object HttpContext.Current.Request
To read the posted content 
StreamReader reader = new StreamReader(HttpContext.Current.Request.InputStream);
string requestFromPost = reader.ReadToEnd();
To navigate through the all inputs
foreach (string key in HttpContext.Current.Request.Form.AllKeys)
{
   string value = HttpContext.Current.Request.Form[key];
}