Content negotiation for index page

I'd like to have different default pages for my site depending on whether it's
accessed from a cell phone browser (content type text/vnd.wap.wml) or a regular
web browser. It looks like it should be possible to do this, but I haven't been
able to figure out how to configure it.

I was able to add the wml extension to the default indexer successfully, so that
files with a wml extension are being sent as the proper content type when
requested by name. I'm using Jigsaw 2.0.4.

  - Dennis