I have two spreadsheets that contain names, addresses, telephone numbers,
etc. of prospects. Both sheets have about 4000+- contacts. I want to
compare the two and accomplish a couple things but i'll just start with the
first and go from the

I want to see what companies are found on both lists so that i can compare
the names and addresses and update one list against the other (one is new and
one is old).

Any ideas on the best way to go about this?