This app & service have been discontinued, with Mac users especially put out to pasture. They are recommending Pando.com and I personally recommend YouSendIt.com and GetDropBox.com as well.
From their web site:
"VIPeers & Podmailing Beta Closed for Now and Shall Return with PUMP
I know this might come as a disappointment to some of you fans of VIPeers, but we have to close the service for the time being. The VIPeers / Podmailing beta-test has been suspended, enabling our team to do a complete overhaul.
VIPeers will be back with a brand new file sharing service integrated into Pump, our Video software for Windows XP/Vista which is currently in private beta. In fact we would like to invite you to try this powerful software which will help you to better enjoy Internet video from all sources. You can download it from http://pump.vipeers.com/ using invitation code PUMP-FOR-ALL-VIDEOS.
Thanks for your support so far and keep following us in real time on Twitter: http://www.twitter.com/vipeers"