I have a Netgear Smart Switch which will report the MAC addresses of all devices attached to each port via SNMP. I.E. you can see the device MAC address(es) connected directly to Port X, or connected to another part of the network which connects via Port X.
I have found this is a really great feature if you need to discover which cables are plugged into which port. I'm now looking at buying a number of Cisco SLM2048-G5 and SLM2024-G5 switches and would like to check that they have the same useful feature.