mojo

It's probably been said before but your best bet might be to get an old 486 (mine from from the tip) and use that as a router. Try IPCop, that has MRTG built in.

One nice thing about this solution is that you can use it to get around all the NTL related cock-ups. With a Linksys router, very often the DHCP would run out and not automatically renew, killing overnight downloads or online games. I set up a cron script to automatically renew the lease if it was less than 6 hours, repeatedly every 10 seconds until it's over 6 hours again. You can also run a transparent web proxy and dns cache, which reduces your bandwidth use.

Compared to the Linksys, it can cope with things like eMule which opens 500 connections at a time. The Linksys tends to drop them randomly after a while.

I reckon the 486 costs about £2/month to run, and cost me nothing. I modded the PSU fan to run on 5V so now it's nice and quiet too. I'd look for a low end Pentium or Cyrix though, as the web interface is a bit slow on a 486.

Tip: If you are already using a Linksys or other router, try changing the routers MAC address to the same one as the WAN side NIC in your 486 and registering it with NTL first. Then, when you swap over to the 486, you won't have to register and everything will just work.