Sounds to me like you have 2 possible angles to attack this problem:
use SNMP to query the switches to see which IP is on which port.
Its been a long time since I've written an SNMP poll for a switch, but if I remmember
right I think the info you want is in the Bridge MIB.
The static IP's should be pretty easy to locate. For the
dynamics you could query the DHCP server(s) to see what MAC a particular
IP is assigned to. This may or may not be doable (and may or
may ont be doable via SNMP), it depends on the capability of your DHCP server.