Comment Re:Do any of us know how much we really use? (Score 1) 48
One tool I use with a laptop (but it could easily be installed on a Linux or BSD-based router, is VNStat - humdi.net/vnstat/
It can monitor and report hourly, daily, monthly, etc and you can easily chose what interface to report (it monitors all active interfaces). There's also some graphics reporting capability, too, but I just use the command line output and awk-parse what I need.