Commander,
KMZ files are just zip files with a different file extension, so you
can open them with any zip reader (winzip, winrar, gunzip, etc).
Assuming you're on windows, you can do the following:
1. Unzip all the KMZs to KMLs into some directory
2. Run a search on the entire directory for "<coordinates>" in the
contents of all files. (<coordinates> is the XML tag within KML that
holds the longitude,latitude,altitude for a point, in that order)
on linux/OSX:
2. just grep all files for 'coordinates'
Hope that helps
-ns