Thanks for the above posts. I ended up using XZip as my zip utility (http://xstandard.com/en/documentation/xzip/). Just install the dll somewhere and register it using regsvr32.
Below is a code snippet for anyone interested. It's a working copy (but it does work!). I still have to clean it up using relative paths and MapPath.
'Initialize stuff for zip file
Dim folderPath, zipFilePath, fsoZipFile, fsoTxtFile, objZip
folderPath = "D:\wherever\" 'The path to the files to be zipped
zipFilePath = folderPath + "myzipfile.zip" 'The path and name of the zip file
'Create an empty ZIP file
Set fsoZipFile = Server.CreateObject("Scripting.FileSystemObject")
Set fsoTxtFile = fsoZipFile.OpenTextFile(zipFilePath, 2, True)
fsoTxtFile.Write Chr(80) & Chr(75) & Chr(5) & Chr(6) & String(18, Chr(0))
fsoTxtFile.Close
'Copy files into the ZIP file
Set objZip = Server.CreateObject("XStandard.Zip")
objZip.Pack folderPath + "filename.png", zipFilePath
objZip.Pack folderPath + "filename.pgw", zipFilePath
amallen9867