i use PCE from forensic software http://forensicsoftware.co.uk/FSL_PCE.htm
they did a presentation at a bgfl thing not so long ago an i had looked at there stuff before, after that they gave me a trial so i could install it on my server and i think it allowed 15 client installs
and i played with it for a while and brought it, cost depends if your primary or secondary
primary cost ent too bad but i think secondary in comparison is a bit over the top, the LEA were negotiating a discount which i was promised to get back the difference which is something i should check up on now i think of it
i will say one thing tho the ammount of false positives sometimes makes going through logs teedious and time consuming, if you know the keywords you want to look for or the users there is alot of filtering in the violation reports bit that can help but if you want to look through every "violation" then expect a fare few false positives,
perhapse there is a way to lessen these but i have nto yet investigated that
coupel of other features i liked:
you can have different categories for different OU's and setup customised logins for staff to access the database of violations
i was very impressed with it an b4 u ask no i dont work for them