Do you mean each IP connecting to you? Or each IP you have on the server?
If #1, then I know of no way that could be done.
If #2, then I know of no way it can be done "live" but you can combine iptables + mrtg and get per IP usage over 5 minute averages.
Dan - Vice President - [email protected]
BurstNET Technologies - http://www.burst.net