I don't know of a software that does this on the Cisco switches. But there is a way to get around it. You can specify the MAC addresses of users PC's that you want to allow in. You can apply this on one port or more.
But I recommend that you continue your search for that software. Another way is to use Cisco Secure ACS3.0 which you can install on a Windows 2000 server. But this requires a router (NAS) to work with it. Not a cheap solution!