When last I visited it, I fell in deep like with Oops!Backup's well-designed interface and its plain, straightforward English dialogs. Version 3.0 ($37, 30-free trial) is even better in that regard, and improves in other areas as well. It's still a very capable versioning, continuous-backup utility, but now you can duplicate your backup to a secondary location, as well as specify a network location using UNC (Universal Naming Convention, e.g. \\Server\MyBackup\) instead of having to map it as a local drive.
Oops!Backup saves all versions of the files it backs up, and it does so using delta technology, meaning it saves only the changes. This can significantly reduce disk space requirements. When you need to restore a file, you choose a time from which to restore, and your files as they existed at that point are restored. There's nothing like the fancy scrolling of Apple's Time Machine, but it's an elegant process nonetheless.
Version 3.0 sports two new features to control backup behavior. The first is a blackout period, which lets you prevent the program from operating while an online backup program or other important process is engaged. The other new feature limits the amount of space used on a drive to retain older versions. Both are welcome additions, as is the ability to remove a file and all its versions from the backup, and prevent it from being backed up in the future, from within the restore pane.
My quibbles with this program are minor. Selecting files is a bit of a stiff process, and I could do without all the chatty messages designed to prevent beginners from wasting space. But those are things you do only occasionally with any program. I liked the point-in-time restore function, and Oops!Backup's continuous protection performed flawlessly in my tests. With the improvements, it's an even more worthy contender for your local backup dollar.