Employee Monitroing through Hardware Solutions

Hi all. I've heard some devices (like Sonicwall firewalls) can perform network monitoring, as in, deliver a report to the admin as to which sites have been accessed by which IP in a certain timeframe (say, a month). I have a client who's looking to monitor his network for employees slouching, but to do so cheaply and easily. I'd welcome any suggestions you guys might have. I know there's software that does this, but I believe he's looking for a simple hardware solution. Does anyone have any suggestions?

Hi all. Thanks for the responses. I actually believe my client's intent isn't nearly as Machiavellian as I might have phrased it. It's much les of "Let's see what Joe's doing every second of every day" and more of "Joe's been turning in stuff late for 3 months and we're about to let him go. Has he been just playing around this entire time?" He - the client - doesn't even want to know how to access the information - he simply wants to know he can hire someone to retrieve it if legal disputes arise following a firing (and believe me - that's a high-morale office... you'd have to really screw up to be let go).
Sorry if there was misunderstanding. I know Sonicwall does some sort of monitoring, but I didn't know how comprehensive the logs were or if they were adequate for what he desired. 

I hope this clarifies. Thanks so much for everyone' who's given me feedback and is taking a look at this. I hope this helps someone else in the future as well.

Now THAT is funny. I recall paying my employees to WORK, NOT to surf the internet  And we wonder why more and more jobs are being outsourced to someone who WANTS TO WORK while they are at WORK