The security implications (which dropbox do not take seriously) of this are a nightmare. I feel sorry for all of the network admins and security people who have to deal with the fact that all of their employees are unintentionally exfiltrating everything.

I'm building one

OK, at work we use Sharepoint to collaboratively edit and push out data to colleagues as Word and Excel files.

Will your app let me do the same kind of thing at home with outside work friends and the voluntary work I do?

I think Dropbox would already enable the collaborative edit and push thing you described with outside work friends, depending on how you define "collaboratively edit".

On top of that, it should be easy to build a web app to accomplish the same thing, plus some extra elegant features.

The question is, would you pay for it? ;)

Can you check files out with DropBox, so you don't have two people working on a file (since presumably they don't have merge working for Word/Excel docs).

I seriously hate your use case. The locked file is the most troublesome thing that seems to negatively impact everyone using these systems so one person can, once in a while, ensure no conflicts happen. A better solution would be smart merging. Just look at source control to see how half-assed locking is as a solution to this problem.

/end-rant

I think this sentiment is reason enough to always leverage source-code control for something like this. They've been working on the problem for an ultra-long time in computer terms, so adapting one's use cases to the capabilities of existing foundational components is probably the quickest way to long-term happiness in the revisable storage world.

SCC works great for text files. In my Dropbox I ha e Excel, Powerpoint, PSD, Keepass, Installers, PDF, MP4, MP3, etc...

Of you have a smart merger for all of these integrated into Dropbox, send me a link.

They don't have merge working for _anything_. They simply bypass it by noting that the same file has changed on two computers at once and saving two copies in the folder, for the users to merge themselves.

Much safer that way.

Yep, you could do that rather easily with a web app + Dropbox API.

Have y'all tried Box.net?