let\'s say I\'ve got a file called foo.html sitting (quite comfortable) in my assets/www directory (next to my index.html).
I\'d like to copy that file
You should be able to access the file this way:
window.resolveLocalFileSystemURI("file:///android_asset/www/foo.html", onResolveSuccess, onFail);
You can then use the File API - FileEntry.copyTo or FileEntry.moveTo to actually do the action. Note - you cannot actually write into the assset/www folder, only to an SD card.
Hope this helps