This is how they do it on my short Embraer flight... they are actually quite efficient with it. Basket with snacks, and a little tray that holds 9 or 12 drinks. The FA's would have to get into a good flow but I could see it working. The one flight attendant on my flight serves 25-30 people with plenty of time to spare. Not so sure this would work well on the really large flights, but I don't fly those often so I don't know FA : passenger ratio there.