In my experience, ntop is only useful for diagnosing problems, as you cannot leave it running for too long without it killing your CPU.

ntop brought our 4 core intel machine to a standstill after a few days, it's ment for quick diagnosis but not long term monitoring.

On a side note - I like trafshow much better than ntop, I wish they would have continued developing trafshow instead of converting it into the web-based, memory sucking nightmare that is ntop.

Just MHO. Have you had success running ntop for longer than a few days?

While this won't track URL's, we use Argus for tracking bandwidth/host usage.

It's got a nice client interface to insert data into MySQL, damn near real-time, I can pull accurate reports within 30 seconds. Unfortunately the MySQL feature is kinda new & there's no really good web interfaces.

Not really an out of the box solution either, but it's free & if you're familiar with MySQL and web development, you can make a nice reporting interface fairly easily. I whipped one up with jQuery and flot for charting over a weekend, and tied it into our inventory database. It'll show network utilization grouped by the local source, with a count for bytes sent/recv for each remote host. But it's layer 2-4 only, so no URL's are reported.

One of these days I might release my web interface for Argus, but the code needs cleanup and commenting so eh...I wouldn't expect it any time soon.

http://www.qosient.com/argus/

My super-strong RSA encryption modulus was (2^43,112,609-1)*(2^42,643,801-1) and now it's broken. So much for 85,756,410-bit encryption.

and even one more difference, from TFA:
Organizers said the trio was caught when they took their purloined password prizes to Wall of Sheep workers and asked them to post the information. The workers refused.

So...they turned themselves in.

On June 5*5 2*7*11*13 WorldCom revealed it had overstated its earnings by more than $2*2*2*2*2*2*2*2*2*5*5*5*5*5*5*5*5*5*7 by improperly accounting for its operating costs. Senator Paul Sarbanes then introduced Senate Bill 3*3*3*3*3*11 that same day where it passed 97-0 less than 3 weeks later. The House and Senate formed a Conference Committee to reconcile the differences between Sarbanes's bill and Representative Michael Oxley's bill (HR 53*71) and on July 2*2*2*3 2*7*11*13 the Sarbanes-Oxley Act of 2*7*11*13 was passed.