Ethiopia draws a lot of interest from the development industry. Both USAID and GTZ (German development association) have their largest missions in Addis. So there is a fairly large Ferenge population. They/We tend to gather at the same coffee shops and restaurants: Lime Tree on Bole Rd., Castelli's in Piazza, Serenade up by amest kilo, the riding stables on Sunday mornings. Because we're all in the same boat people tend to be fairly open to making and receiving invitations for social activity. It's easy to get included on the bike-ride e-mail list. You can always find someone to go for coffee on Sunday afternoon. Social groups tend to group by language, e.g., the first party I went to here was attended by Americans, Brits, and Canadians. This is not always the case. We spoiled Americans enjoy the fact that most expats speak English pretty well, no matter where they're from.
One quick connection maker is the Mom network. As soon as someone with young children moves in, or even before they move, they get plugged in, via e-mail, to the play-group network. Mothers and others (the occasional stay-at-home dad) gather to let the kids play, and to drink wine and talk. Sometimes moms bring the Nannies so they can converse more easily. Sometimes the Nannies come without the moms. Anyway, these play group connections also become non-kid social connections, for dinner or whatever.
The itinerant nature of people's postings here (most are two years) keeps relationships somewhat less deep than they might be otherwise. For people who like to have lots of acquaintances this is an ideal situation. For those who prefer a couple of deep friendships, it's not.