Eightythree Technology has Phone Drive (iTunes Link) for the iPhone, iPod Touch, and iPad in the iTunes App Store for FREE (regularly $1.99) for a limited time.

You can now use your iOS device as a portable Wireless Flash Drive. Introducing Phone Drive.

Phone Drive allows you to store, view and manage files on your iPhone or iPad. You can connect to Phone Drive from any Mac or PC over the Wi-Fi network and transfer files by drag & drop files straight from the Finder or Windows Explorer.

Phone Drive features document viewer, PDF reader, music player, image viewer, voice recorder, text editor, file manager and support most of the file operations: like delete, move, copy, email, share, zip, unzip and more.