802.1x, performs port authentication, the switch will do all of the authentication negotiation on behalf of the client. This requires an authentication server, there are free ones available, ACS can provide the authentication and even Microsoft has a product. It works very similarly to what you had probably configured for your wireless authentication.
Another option (definately not top on my list) is to use VMPS, this will dynamically assign VLAN's to a port, if the mac-address is not in the VMPS database it will not assign a VLAN to the port and the user will have no access.
HTH,
Craig