Collaborative recording from two different locations

Does anyone know how two composers can collaborate on the same tune from two different locations? In other words, a composer in New York City being able to manipulate the Sonar data on his screen, and a composer in Miami watching the changes on his screen in Miami.  Thanks….

3 of my brothers and I collaborate on projects in 4 different parts of the country, but not in real time. Now THAT would be cool! I'd be interested in learning more, if such technology exist.

All of my domestic and international collabs have been a process of sending things back and forth..... nothing in real time. Although skype could allow that easily.  I have not looked at the other options mentioned but with technology these days, I'm sure there are some really cool ways to collab in real time on the net.

Could maybe a remote desktop client type setup allow for something like this? I don't know much about that stuff but I think the whole point is being able to control a computer in an entirely different location. I'm guessing that one could control Sonar in this way. Not sure how you'd get the audio there but perhaps having a live audio stream setup just for monitoring the performance while tracking would be acceptable (as both parties record their own parts directly into their Sonar installation) and then after the session is done you just send the higher quality waves.
 
There are probably all sorts of problems I am overlooking like sync clock issues but seems feasible. I think remote desktop stuff for MS is expensive though. I believe Linux has free remote stuff but of course Sonar doesn't work on Linux. Reaper does though which is fine for tracking.

Not Sonar, but there are several Remote Music Collaboration Software packages out there.  Google Ohm Studio, Blend or Audiotool.
 
I have not used any of these packages and don't know much more about them.  In fact I just read about them in the Sound On Sound mag I picked up at Gearfest (June issue, I think.)

We have been collaborating long distance for quite a while now, mostly with the use of Drop Box and uploading project files and recorded tracks. Live would be nice to work out parts with one another, but I can't see finished recordings being done live.

Guitarhacker
I wonder about the latency. 
 
The several times I have used Skype to talk to a buddy, it was like communication to the moon.  A serious delay in the signals made communication shaky, at least until you understand that you need to wait 3 seconds or more to get a reply back.  And if the other person hesitates to think.... man that really messes you up.

Yeah, I don't know how well it would work trying to play together.  My guess is that its "Hey check this chord progression out."  [plays chords] and other guys says "Cool, get it down and loop it and I'll play some lead."