With the recent release of Google Drive, Dropbox isn't giving up any time soon and has got another trick up its sleeve to help you get more free storage. They just announced via their blog a new update for Mac and Windows which enables you to backup your picture automatically. This was already announced for Android a while back, but has now been adopted in the desktop version.
That's not all though, if you use the automatic picture backup feature you'll also be given an extra 3GB of space. You'll first be given 500MB for your first upload, once you use that up, you'll be given another 500MB until you reach 3GB.
Now isn't that kind of you Dropbox.
You can head over here to download the new version.