Hi 4 engine,
I'm not sure this is entirely what you're looking for but we have our own HF radio installation and from time to time for various reasons to do with HF and how it works we have patchy coverage. We have an account with Stockholm Radio in Sweden and they have a super set up so whenever our crews cannot reach us they contact Stockholme who then relay the message to us via email and vice versa. It works well for things like mvt's and short messages although there is a cost.
If you are talking about something that allows you to transmit to an aircraft with some sort of VOIP service such as Skype then I have to say I've never heard of it although it sounds like a nice idea but would need some sort of relay station at the very least or else some internet connection on board the aircraft. In that case you wouldn't even need the HF radio at all.
Stockholm can also do a phone patch for voice to voice comms.
All the best.
Last edited by desertopsguy; 5th December 2009 at 12:53.