Uhm, this may seem too obvious, but I just use the hose connected to the CO2 tank. I take the fitting (to the keg) off and insert into the carboy. Since I force carbonate a lot, this seems to work well without a lot of extra effort. I put the carboy on the floor (or whatever position it will receive the liquid), fill with CO2 (3-5 seconds is good enough for me), and then syphon away. Rick seems to have this to a real science. I have not tried keg to keg. Mark