Hmmm.... well I guess you need to figure out some way to automatically split the file into chunks, then download a chunk, play it, in a seperate thread download a second chunk, when the first one is finished play the second, delete the first, then download a third.
I can't say I have much expertise in the area, but as I mentioned it's a very interesting idea.
You could look at somthing server side like segmenter
http://stackoverflow.com/questions/9...nks-under-unix
But I have never tried this myself. What progress have you made so far?
Live long and prosper