While you can share and take photos from the Dropbox app on both iOS and Android, reader Java-Princess shows us that on Android, all you need to do is start up the Dropbox app and hit your phone's camera button.
If you start the Dropbox app on an Android phone before using the camera, your pics save to your Dropbox folder and from there automatically sync to your PC or Mac, no thinking necessary.
It isn't anything revolutionary that you couldn't do before, but it is much faster than the more well-known method (which involves going into Dropbox, hit the menu button, pressing "New", and choosing Picture from the menu). Instead, you can just open up the Dropbox app, hit the camera button on your phone, and snap away. Any pictures you take will automatically be saved to your Dropbox folder, which is certainly a heck of a lot faster than transferring them to your PC yourself.