Rob[atSound-Rehab]
for simple types of data exchange dropbox is OK (like sharing mix stems as MP3) ...
for real work people need to meet in the studio anyway.
Ever notice that none of those online collaboration sharing services (like Digital Musician.net, Rocket network, etc.) ever got off the ground? As my friend Dr. Walker said about online collaboration, "If I can't look you in the eye while having a beer, it's not collaboration."