In a word, no.

You can use MSN Messenger but as far as I am aware, it is only 
compatible with other MSN Messenger clients and dependent on MSN's 
servers. You probably want to do standard H.323 (or possibly SIP) IP 
videoconferencing. This way you can conference with any H.323 clients 
including any number of PC based and turnkey videoconferencing systems.

Polycom PVX <,,pw-7953,00.html> is 
a software only (BYO PC & USB cam) example of a quality desktop H.263 
application with file transfer, security, etc. features. For a few more 
bucks they also sell a desktop product that includes a camera.

my .02,

Danny G Smith wrote:
> I need to setup a PI with a webcam and audio to go across the pond.  I 
> am being pushed toward MSN, is that the best?