Using a user css file in a webview

Hey all,

This has been done a lot, notably by apps that load wikipedia on the iPhone. I've been looking through the documentation, but I can't figure out how to do it.

I want to load a website in a webview using my own css. How do I do this? I can come up with the css fine; just need to know how to apply it to content that I load.

Thanks!

- Charlie