Have you considered using the Content Deployment features? This should work
very nicely.

If you are looking to backup  the entire site collection then I recommend using
the stsadm utility. Your command line should look something like this:

stsadm.exe -o backup -url http://servername/site -filename
c:\directory\filename.dat

To restore:

stsadm.exe -o restore  -url http://servername/site -filename
c:\directory\filename.dat

If you only want to backup a site, then use:

stsadm.exe -o export -url http://servername/site -filename
c:\directory\filename.bak

To restore:

stsadm.exe -o import -url http://servername/site -filename
c:\directory\filename.bak

Speaking of subject lines, it looks like I messed that one up!
Please respond to this one to keep the thread in tact.