RESTful services with CI

[eluser]trice22[/eluser]
I'm very interested in this idea. I'm currently playing around with the files provided here:
http://blog.medryx.org/2008/10/03/codeigniter-rest/
and things look pretty interesting.

I'm wondering, if anyone as implemented successfully a response type recognition, so that also type like JSON and XML could be requested. —I'm pretty sure I could provide a base model that could generate a the responses.

Another question that came to my mind was how to send additional parameters like paging and filters using "pretty urls" in such a service. The router extension at http://blog.medryx.org/ doesn't allow me to do this. Has anyone had any experience or advice in this case?

Every hint towards a RESTful CI would be highly appreciated. I've found a couple things here on the forum, but nothing is really flexible or "matured" enough to be used.
I can try to write my own, but I guess it doesn't hurt to ask, if anyone could provide some guidance.

Cheers,
—trice