I started out thinking I'd be using Perl (just because I program in Perl a lot), but then it didn't look like any of the Perl OpenID libraries supported OpenID version 2 yet...
How are you integrating with Perl, just out of curiousity?
Yup, that's essentially the same approach as I'm taking (at least in terms of connecting Arc to another language).
Well, if any of the code I'm writing turns out to be useful to you for your project, you're welcome to make use of it... it's all in the public domain anyway :)