MI-L Count Question

[Morris, Rich]

Listers,
    I would like to ask for some help.  And it is probably a simple
solution, but I can't seem to find it.
    I have a spreadsheet of utilities operating in certain Zip codes.  So my
table has the State, Zip, and Utility.
    I would like to find a quick way to see if there are more than one
utility, according to this spreadsheet, operating in any given zip code.
    Or in different terms, I want a list of all zips with more than one
utility.
    tia for your help.
rm