Since Dropbox itself is a free service, it's a pleasant surprise to see a simple, easy method for creating a new Dropbox account right off the bat if you don't happen to already have one. The app just asks for a name, e-mail address and password, prompts you to accept the terms of service, and creates the account. During my testing, I did encounter a problem where I would receive a nondescript "Account creation failed (null). Please try again." message, which I'm guessing may be due to high load on their servers. Still, this is not an encouraging encounter for new users.
Once logged in, everything worked pretty smoothly. On first login, You are presented with a brief welcome document that highlights some of the features of the app. Backing out of the document will take you to your Dropbox, which quickly lists any of the files and folders you may have in there. The app features built-in document preview for several types of files, including PDFs, text documents, spreadsheets, pictures and videos. You can also tag files as a favorite by tapping the star at the bottom of the file viewer, which adds the item to the favorites panel and caches a copy locally on the device so that it's immediately available.
An unexpected feature is the ability to take pictures, video, or use existing media and upload them directly to the Dropbox. This could definitely be handy if you need to take a quick video and have it available on another machine without having to plug in your phone and wait for it to sync. Also unexpected, but incredibly welcome, is the massive amount of documentation that is available from inside the app's settings panel. In addition to giving you general details about your account, the settings panel offers a link to watch a video about how Dropbox works, take a tour of the features, or browse their complete online help library, without having to leave the app. As many apps fall short in this area, it's refreshing to see such detailed documention available, let alone right from the app.
A couple of side notes: As I mentioned above, the new user signup does not appear to work properly sometimes. I'm guessing this will be fixed in short order, though. You can log out of your Dropbox account by tapping the Unlink iPhone from Dropbox button on the settings panel, but beware that you will loose any favorites you have stored (the app does warn you of this). And finally, when you do logout of your account, the app just disappears from the screen, as if it crashed, although you are successfully logged out. In my eyes, these are minor issues (well, aside from the signup problem), and will likely be addressed with future updates, but still good to watch out for.
All in all, this is a very well done, simple app that connects you with an already great (and free) service. It's available now in the App Store for free.