Mailing the story:

I've tried many different things in the hope of solving my Gwibber/Me Menu/Social bar problem in Ubuntu Lucid. That problem, for those not reading along (you're the better for it, I assure you) is that for some reason even after I start Gwibber and send a social-broadcast message (to Twitter in my case), the "social bar" in the upper panel's Me Menu does not appear. Here's how I finally "fixed" my Gwibber/Me Menu situation.