There is a wonderfully brilliant piece on NPR this morning that presents a case study of the intersection between online contacts and in-person follow ups. If I believed in tagging, I tag it something like:
awkward social encounters
Here's the current link.
If that doesn't work, it's been moved to the archives and you'll have to find it there. The piece is titled "How iMet My Neighbor on iTunes" by David Kestenbaum, and it was broadcast on the January 12th Morning Edition.