Windows only: Octopus is a lightweight media indexer that sorts and searches your data across flash drives, burned discs, and other removable gear. If you back up your data to an external drive, you've got half the equation down; when it comes time to use and restore it, though, the free Octopus takes only a few seconds per disc (or drive) to create a quickly searched index. Like the similar multi-indexer Virtual Volumes, Octopus lets you locate needed files by folders, file names, file sizes, creation dates and attributes. Better still, you can tag individual files and entire indexes with keywords, and search using wild cards and narrow results by file size, modification date, and other factors. Octopus supports floppy disks, CD/DVDs, and removable flash based media like thumb drives and SD cards. The big drawback is that it treats external hard disks as fixed disks and won't index them. Octopus is freeware, Windows only.