HL2: Backing up Steam?

For those of you who have downloaded the steam install of HL2; has anyone run a registry and file tracker during the install? That way you could create a reg file and identify the locations of files which are installed. It would be great if the install and reg file could then be copied to DVD for easy reinstall at a later date. I know you’d still need to work through steam at some point, but getting 3+ GB of data back on your PC quickly and easily would be a bonus.

Right > Click game in Steam, select Backup.
You want it easier?