A quick tip, this one.
I use Dropbox to work on the same projects from two different machines. I also like accessing my various Dropbox files using the Dropbox app for iPhone, but there’s no easy way to view Scrivener files on the phone even if you can access them.
However, you can get part way there. A Scrivener project is in fact a ‘package’ or ‘bundle’ on the Mac; it’s just a folder that’s been marked in a special way so the Finder and other apps treat it like a single file. You can see inside by right-clicking and choosing ‘Show package contents’, and you’ll find that Scrivener, very sensibly, stores the content of your project inside the package in a set of nice standard formats, like RTF and text files. (If you want to try messing about with the contents, please do it on a project which isn’t important!)
Now, this interior of the package can also be seen using the Dropbox iPhone app, which will just treat it like a folder, and so will allow you to view a lot of the files inside. They won’t have very helpful filenames, but you can browse around, view the contents, and even copy and paste bits into emails to your editor 
I wonder if it is possible to poke around in that Scrivener package on a Mac and locate the documents that you’re interested in publishing. On a Mac, you could then create separate Dropbox folder with an obviously named alias to each of those documents (i.e. Chapter 1, Chapter 2 etc). Given how confining an iPhone screen is, that could save time.
But what happens to that alias when editing Dropbox on an iPhone? Is it a null file? Is it the original file duplicated, in which case editing it wouldn’t change the original? Or does the iPhone and Dropbox know about file aliases, in which case editing the alias would edit the original?
I’m not using this scheme, but someone who is might want to see what happens. If an alias works, it’d save a lot of time and trouble.
–Michael W. Perry, Seattle
Symbolic links are the preferred method, using DropBox, according to their documentation. On another Mac, accessing an alias might work (I’ve never tried it, but it wouldn’t surprise me if it doesn’t because DropBox has issues with some types of special Mac files like that), but symbolic links work everywhere—in fact you can even have them poking out into any other part of your disk and DropBox will keep that file up to date even though it isn’t in the DB folder itself. Very useful if you want to keep some stuff synchronised, but also organised where it should be, and not all in the DB folder.
Unfortunately, making symbolic links isn’t well supported on a Mac without either some use of the command line (sym links are along for the ride, thanks to the Mac’s UNIX core, and probably for no other reason), or a third-party tool like QuickSilver or LaunchBar.
Now all of that abstract aside: it would not be a good idea to use this trick to edit the guts of your Scrivener project using the iPhone or what have you. Scrivener keeps track of the contents of everything, this is what makes its searches so fast. If you edit its files outside of Scrivener, it will lose track of things and potentially end up getting mildly corrupted. But for read only access to the internal files, that should be “safe”. Probably not the best practice in the world, but if one is careful it shouldn’t cause any harm.
What I’d recommend instead is the use of Scrivener’s export feature. Not only will that dump out all or some of the Binder into clearly labelled (and organised) files (no poking through a list of hundreds of serial numbered files), but it will let you see your meta-data too, such as notes and synopsis. Since DropBox so helpfully tags files that have changed for you in the web interface, it wouldn’t be too difficult to go through that list of changed files and integrate them by hand.