You can get peace of mind by configuring RootsMagic to automatically store backups of your data both on your computer and off site (on the secure servers at DropBox). All it takes is a free (up to 2 GB) account and this video to show you how to configure RootsMagic. Click here to get your free DropBox account (and earn me a small increase in space for the referral—thanks!). There’s a nice video on the DropBox page that will walk you through the installation and usage.
By the way, don’t try to store and use your database from your DropBox folder. It won’t work properly and may cause you to lose data. Just stick with backing up there.