Per IP accounting

I would like to have a better overview of my bandwidht hogs and was wondering if any of you guys know if it possible to set up accounting (and possibly other tools/scripting/snmp) to get a listing of the bandwidth usage per IP of my machines? Preferably in a neat listing along these lines:

IP		BYTES_TX	BYTES_RX
10.1.0.1	876876876	9979622
10.1.0.2	98798798	76876
10.1.0.3	768687		99793473
10.1.0.4	65593737377	976298713

Maybe you can use firewall way http://wiki.mikrotik.com/wiki/Traffic-flow

See /ip accounting

http://www.mikrotik.com/testdocs/ros/3.0/aaa/accounting.php

Will give you what you want, just remember you must collect the data from the unit on a regular basis or you will lose data.