We now have per-IP usage stats available for broadband customers. You can view usage based on your IPv6 and legacy IPv4 addresses. The data is broken down in to daily and hourly totals for upload and download.
The usages is based on 'sampled' data, so will not be 100% accurate, but should give a good idea as to how your usage is spread across your machines.
The data is updated every minute or so.
You can find this from the Usage page on the Control Pages. We welcome feedback.
(Per-IP usage is not being collected for customers using L2TP, SIMs, Ethernet or the 'test LNS'.)
You can do reverse DNS lookups on the per IP stats now.