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.