I believe that portage/emerge uses it, yes.
 I find rsync nicer for most of my needs than FTP or scp.
 typically what I do is this, to push:
 rsync -auv file1 file2 ... user@hostname:/path/to/where/i/want/it
 or to pull:
 rsync -auv user@hostname:/path/to/something .
 It Just Works (tm).
 The only subtle gotcha I've found is that
 "rsync foo_directory ." does not mean the same thing as
 "rsync foo_directory/ ."
 ... this is explained clearly in the EXAMPLES section of the man page.
 Also I generally put this in my /etc/profile:
 export RSYNC_RSH=/usr/bin/ssh 
Paul,
   Thanks. I will save this email for future reference.
Cheers,
Mark