You can get a decent count from show interfaces.

Reliability of the interface as a fraction of 255 (255/255 is 100 percent reliability), calculated as an exponential average over 5 minutes.

txload/rxload=Load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes.

reliability 255/255, txload 17/255, rxload 5/255

Divide 17 by 255 and multiply by 100 get the percentage of the link being utilized (TX only).

If you want to graph this over time, PRTG is good application, all though it uses SNMP and not Netflow to collect the data.

Hope that helps.

PRTG or a collateral SW from the same firm supports netflow also, and that is what is used when you want to know "what" is using BW beside merely "how much".

You can also get Netflow from the router without an application.

http://packetpros.com/wiki/index.php/How_can_I_enable_and_view_Netflow_on_my_router%3F

I do that on some sites. Only, it doesn't produce nice charts for customers, these they can show to executives and random visitors :)

Come on, ASCII isn't pretty? Like in the old days when people would set the login banners with cool art.