MiShell Software's Directory Duplicator--DirDup, for short--is a different kind of backup utility: instead of copying files, it copies directories. It's designed to make life easier for people who take work home with them by keeping the data synced and up-to-date between different computers. It speeds up the job, too, by letting you exclude certain files and by checking file size before you back up files to a slow device, such as a memory stick. It doesn't just compare the size and date of files, either; it does a byte-by-byte check to ensure no changes go undetected. It also validates source files before copying to make sure good backup files aren't corrupted by bad source files, since a bad backup can do more harm than good.
DirDup is small and installs cleanly. We like simple, clean interfaces, but DirDup's sets the standard: just a Copy log, Status window, and Task window. There are basically two controls: New Task opens a Task Editor, and Load runs a preconfigured task. The Task Editor lets you select source and destination, list exceptions, enter file extensions for comparing, and other options. It's easy to automate backup tasks and create shortcuts to them as well. There's a lot of flexibility for the sophisticated user, too.
DirDup definitely speeds the tiresome task of keeping your data straight and up-to-date when you regularly carry it between different computers or use different backup devices, and it helps keep your backups clean and uncorrupted. Best of all, it's free.