Not at the moment. There are rumors that an emulator is up and running, but
hasn't been distributed yet. Considering how cheap the Xbox itself has
become ($120 refurb, $149 new), and how well it works with Xbox Live, I
really don't see much point in it, but that's just me. There's a group of
folks working on it, though. One thing for sure, is that you're going to
need a pretty stout computer for it to work 1/2 way decently.