Access files in dropbox on mobile

[Ben Rubinstein]

Is there any way to access the files in a user's dropbox on iOS or Android?

I see that Monte's awesome external allows my app to download files directly 
from a user's dropbox account to my app's local storage - but if a user has 
the standard Dropbox app on their device, and has files downloaded in that, is 
there a way to access those rather than duplicating the data?

I'm guessing not, but thought I should ask...

thanks,

Ben