The visa situation is very much in a state of flux. The border at Kosi Bay said they would issue a visa on the spot to Commonwealth citizens (and possibly others too). The cost is $(US)75. This year I’ve used the new much-improved Goba crossing from Swazi (now an extremely good road), where visa at border was not available. Nor was it available at the busy Ressano Garcia on the main Jozi to Maputo corridor. But I guess these things might well change according to the mood of the officials on duty.
I found the MOZ Embassy in Berlin was brilliant. They said “allow up to 15 days for a visa” but it took just five. They did however want an official invitation in Portuguese certified by a Moz notary. I had no problem getting that, but I could imagine it might be an issue for some visitors. I guess an invitation letter from a hotel with confirmed reservation might have been an adequate substitute. When I picked up the visa, they gave me a bag full of Moz goodies, first time I’ve ever experienced that when getting a visa for anywhere. Very glossy magazine.style guide to the country, with a decent map, and a handful of leaflets.