Dropbox is an incredibly useful idevice app. It lets you drag and drop files into a folder on your PC and allows you to access them on any other idevice or computer that has access to the internet.
Dropbox features 2GB of storage for the free version and works equally well with iPhones and PCs over 3g or wireless. It supports any kind of file.
Dropbox is an extremely useful free tool and couldn't be easier to use; you simply install the client onto your PC, make an account on the Dropbox website then install it on other PCs or phones you wish to sync. It is of course a free app in the app store.
Once you link all device with your Dropbox login, you simply drag and drop files into the Dropbox folder on any PC, which you can place anywhere and they are automatically uploaded to the Dropbox servers and synced to any other PC or device.
This allows you to have access to text files or photos on the go and allows you to do things like keep an archive on a PC and allow any other PC or device to access it from anywhere, so if you're away from your PC you can access that important receipt or picture.
The app is also useful for content you want on your device but would rather not sync, so it is not stuck on your device till the next time you sync. You could use it for private photos or sensitive text files, as you can lock the Dropbox with a passcode.
Dropbox has a very clean interface. You can view your files by name or switch to a
tiled view of pictures for image files.
Dropbox is completely bug free and I experienced zero problems accessing files and upload times were consistently fast.
There is no downside to Dropbox; It is free, fast and does exactly what it says on the tin. The only possible downside is the 2GB max of storage.
Dropbox is a no brainier app for your idevice. If you need to access files, keep files private or simply want an easy way to share content between your PCs and your phone without syncing, Dropbox is an essential download.