Matt Landis over at Matt Landis Windows PBX + UC Report has come up with a great tool to scan your Outlook contacts and automatically check public DNS to see who might be open to Lync/OCS federation. You might be surprised how many of your contacts have might have OCS/Lync.
Even in my contact list, which is unsurprising biased, I found some old contacts that I didn’t know might have Lync.
Here is a quick rundown of the tool, as always, use at your own risk.
Choose a contact list to scan:
Depending on your firewall policy you may be alerted. The program is checking a local database of known companies with federation DNS records in the app and then public DNS if you allow to reach the internet.
It will then scan all your contacts
And leave you with a list of people who may be able to federate with you

Tom, wanted to say i appreciate this article on the wcf tool. Thanks! Also I wanted to note that some items you have suggested when we talked are now in v1.1 and its up on the gallery.