You have probably realised by now that I’m very interested in forms of communication and the best ways to go about improving them.  What about communications from those you *do not* know?  I can get telephone calls, SMS messages, emails, and Twitter @replies (among other things) from people who have not been whitelisted (aren’t in my address book / on my friends list).  Is this useful? What forms of communication suit it best?  This poll started on Twitter, and I’m continuing it here and on PollDaddy.