ive been having a few issues with steam backups, i use the above method using the steam backup tool, select it so it creates a big file that i just copy to a folder rather than dvd sized files but then i run the app to reinstall them all it does is says preparing game files etc then it just starts downloading the games again which pretty much seems a waste of time creating a backup?
*edit*
Ah my bad, just realised you need to copy the folder locally to do it, is that right?