command for finding interfaces which have not been used on cisco switches

Only available on 4500's with supervisor
# SHOW INTERFACE LINK

# show int | i proto|Last in

# show int | i proto.*notconnect|proto.*administratively down|Last in.* [6-9]w|Last in.*[0-9][0-9]w|[0-9]y|disabled|Last input never, output never, output hang never

This last command and filters out text you don't need.