Just released a new version of Own-Id. Now gives more detail in error messages.
Incidentally, we now have 188 ids now on Own-Id. As ever, I'm always keen to hear about your experiences with Own-Id.
For testing Own-Id on my local machine, I use the MyId OpenId server which is great because it's so simple to set up, and it uses Digest Authentication which is a RESTful method that makes testing easy. For me, the one problem with MyID is that is uses a META tag to redirect the browser, but I find it easier for testing to have a HTTP 302 redirect, so I modified the source (just a simple change) to achieve this.