Using Office 365, you also get Lync 2010, and additional you can activate Federation which means you can add external contacts (who are not part of the same domain) if they also use federated Lync.
Today, Loryan Strant tweeted the following:
Naturally, I got very curious and wanted to find out who of my Outlook contacts might be a potential contact for my Lync.
If you follow through various links, you end up at the Microsoft website where Matt Landis provides a free tool named “Who Can Federate”. Installation is quite easy, simply download the ZIP file, extract its contents, and run Setup (no need to configure anything). Once you start the tool, the UI is fairly simple. It allows you to select whether you want your Outlook Contacts or Suggested Contacts (only Outlook 2010), and start the scan. Once you start it, it verifies all the domains of your contacts for potential Lync Federation capability, and lists all matches:
Finding a match does not guarantee that adding this contact to Lync 2010 will work and that you can chat (text/audio/video) with him, so to find that out you still need to add that contact to Lync (needs to be done manually, cannot be done from the WCF Tool).
The huge benefit of this tool is of course that it provides you very easily with potential Lync contacts from your existing email contacts. No need to configure a lot, just run it and get the results! Perfect!
PS: Add me at rene @ office365management.com