I'm only familiar enough with netapp out of the nas/san vendors to feel like I can speak authoritatively, but netapp has a feature to audit cifs (windows file sharing) access/modification. Throw "cifs file auditing" into google and you'll get some results. This will only really give you auditing at the first level of access, if someone accesses it legitimately and then passes it on you're out of luck, but you'll have a list of who accessed the initial file at least, which may be enough.

Anyway, YMMV, but if you've already got netapp or some other storage vendor, it might be worth looking into.

College isn't cheap - and in most cases certainly isn't free (even if it is, someone's paying) - so why the heck are you turning to slashdot when you've got someone who teaches the course you could ask. If they're too busy to field the question then you should be yelling at someone about not getting your money's worth.

Just my 2Â,
Nick