On a 6500, or any layer 3 switch for that matter you have 2 choices as far as routing and routed interfaces. You could configure an ethernet or fiber port on a switch as a routed port. This would be like the ethernet port on your 2800 router.
The other option is creating an SVI interface that represents a routed interface for a particular vlan. So, lets say I have vlan2 on my layer 3 switch. I would then want to create a Switched Virtual Interface for that vlan.
#(config-if)ip address 10.10.10.1 255.255.255.0
You now have a virtual interface for vlan 2 with the IP of 10.10.10.1/24. Because this interface is directly connected to the switch, it is in the routing table of the layer 3 switch. Think of the SVI as a couterpart to a routers sub interface. They are both virtual interfaces. One is tied to a physical interface, the other tied to a vlan.
Also, some layer 3 switches actually come in ip routing mode by default, like a 6500 or a 4500, so you wouldn't need to enable IP routing on those types of switches because it's already on by default.