The Virtual Volumes View (VVV) project lets you index your data DVDs and perform searches to figure out whether a given file is backed up and what disc contains it. If you routinely back up a large amount of data onto DVDs, you can simply number your discs and keep them in numerically sorted order. When it comes time to find an image or digital video you burned to DVD, just use VVV to figure out the disc number and quickly locate the right disc in the pile.