I have noticed that some WPF controls have some decent effects available to them (drop shadow, reflection etc), and was wondering if it was possible to use these WPF controls so
You can use them, yes. The only problem is that you have to use them within STA threads, which you probably can't count on happening automagically (e.g., response threads in ASP.NET are MTA).
I'm using WPF controls in a windows service app. I just have to transition to an STA thread before I do my rendering.
Take a look at RenderTargetBitmap. You could do whatever with your WPF component, then render it as a bitmap, and then use that bitmap on your ASP page.
I'm not sure that is the best way of doing it though. Is Silverlight out of question for you?