Have you checked out the codeplex download for SUSHI?
"The backup feature in Sushi allows you to create manual or scheduled automatic backups of SharePoint. The SUSHI backup feature is simply a wrapper around the STSADM.exe -o export -url <sharepoint url> command. SUSHI gives you a way to easily build the commandline command without having to open up the console window. SUSHI also allows you to schedule regular backups that will run automatically.