I need to block users from accessing certain web sites at work. Is there a
way to do this via a GPO or by workstation?

Sure you can use group policy. This how to may help.

--
Bob Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN Troubleshooting on
http://www.ChicagoTech.net
How to Setup Windows, Network, VPN & Remote Access on
http://www.HowToNetworking.com
"Vern Orlik" <VernOrlik@discussions.microsoft.com> wrote in message
news:3EECC5A3-0B6B-4032-9D23-D1E3BFFFFD04@microsoft.com...
>I need to block users from accessing certain web sites at work. Is there a
> way to do this via a GPO or by workstation?