If you move to 12.2(52)SE, you will get EEM 3.2 which offers a lot of capabilities to create custom SNMP traps and syslog messages. For example, here is a simple applet which will send out a trap when a new MAC is learned on the non-default VLAN:
event manager environment default_vlan 1
event manager applet port-vlan-notif
event event mat interface regexp .*Ethernet.* type add
action 001 cli command "show interface $_mat_intf_name switchport | include Access Mode VLAN"
action 002 regexp ": ([0-9]+) " "$_cli_result" ignore vlan_num
action 003 if $vlan_num ne $default_vlan
action 004 snmp-trap strdata "Interface $_mat_intf_name has VLAN $vlan_num"
action 005 end
You could trigger an EEM policy on other events as well. For example, you could also trigger an event on a config change, and send a trap if a port's VLAN is changed by an interactive user. This type of policy would be a little more complicated, but there is an example which could be adapted at http://forums.cisco.com/eforum/servlet/EEM?page=eem&fn=script&scriptId=1103 .
