SanDisk have come out with an app which is probably one of the best utilities out there for the Android platform. With nearly every Android device coming with an SD card this is an app that is definitely worth downloading, especially with it being completely free.
The app lets you backup your whole memory card to the cloud. You can schedule backups so when you're asleep at night, you can be assured everything on your memory card is being backed up to your Dropbox. The app also lets you password protect specific folders so only you can access them.