Get 25 GB of free space for two years
I guess you already have Dropbox installed on your Android device, you must Clear data, Force close and finally uninstall it from Settings > Applications > Manage Applications > Dropbox.
- Download and install the Dropbox+23GB APK Be sure to enable Unknown sources under Settings > Applications or Settings > Security (on ICS) before installing the APK!
- Launch the app as usual and log in.
- Wait for a confirmation email.
- BINGO!! 20GB (ish) more then you already had!
- After getting the extra space, you can uninstall the Dropbox+23GB and install the official dropbox build.
Original story: http://forum.xda-developers.com/showthread.php?t=1550699