From Red Line Software:
Internet Access Monitor is a comprehensive Internet use monitoring and reporting utility for corporate networks. The program takes advantage of the fact that most corporations provide Internet access through proxy servers, like MS ISA Server, WinGate, WinRoute, MS Proxy, WinProxy, EServ, Squid, Proxy Plus and others. Each time any user accesses any website, downloads files or images, these actions are logged. Internet Access Monitor processes these log files to offer system administrators wealth of report building options. The program can build reports for individual users, showing the list of websites he or she visited, along with a detailed break down of internet activity (downloading, reading text, viewing pictures, watching movies, listening to music, working). Plus, the program can create comprehensive reports with analysis of overall bandwidth consumption, building easy to comprehend visual charts that suggest the areas where wasteful bandwidth consumption may be eliminated.