Just a note to myself since I keep confusing this with the Backup/Restore method:
When trying to backup and restore a site you can use SharePoint Designer 2007 to do this, but you can also use STSADM:
STSADM -o export -url <url> -filename <filename> -includeusersecurity -versions 4
STSADM -o import -url <url> -filename <filename> -includeusersecurity
Note the URL being imported into should be created in SharePoint Designer with an Empty Website.