I just discovered this thread, so here goes:
USA (too many cities to list, but my favorite was in New Orleans at a little place called Ali Baba)
Switzerland (where I learned that French fries belong in a falafel wrap!)
South Africa (though I think they were kibbeh and not proper falafel)
India (airport falafel in New Delhi)
Couldn't find falafel in Thailand, Cambodia, Russia or Japan.
Sadly, my favorite falafel shop here in Boston (where we don't have bostonggurka, by the way!) just turned into a Lebanese restaurant. Now their falafel wraps are tiny and they toast the wrap like a panini. Weird. So I've started to go downtown for my fix to the little shop on Winter St in Downtown Crossing.