[boyter]

Not sure about that. I think in that case it just needs to work, without any configuration, installing etc... It needs to be as pain free as possible. Unless DB can somehow be installed by default on those devices I can't see it making the grade.

[fpgeek]

Dropbox is pre-installed on many Android phones, for example: http://geektech.in/archives/6318 (which comes with extra free storage up to 5GB for HTC users).

Pre-installing on PCs is possible, though my quick Googling didn't turn up anyone doing it. Pre-installation on Apple devices is unlikely, of course.