One way to transfer documents (Word, PDF, etc.) created on your desktop computer to your iPhone is to e-mail them to the iPhone as an attachment. You can also use the Yahoo IMAP e-mail service to create a new mail folder which would then appear on the iPhone. However, simpler solutions are available on the App Store.
Files ($6.99) allows you to connect your iPhone or iPod touch to a Wi-Fi equipped PC or Mac and drag-and-drop files between the devices (Fig. 12). In addition, it allows you to view a variety of document formats on your iPhone, including Word (Fig. 13), Excel, Powerpoint, PDF, images, text, html, video, and audio files. The program handles large files well.
Air Sharing ($4.99) also lets you connect to any Wi-Fi equipped Mac, Windows, or Linux computer, move files between the mobile device and the computer, and view documents or play media files in many common formats. The 8-16 GB micro drive on your iPhone or iPod touch provides you with plenty of file storage space. Both of these apps will let you use your Apple device as a portable hard drive with your Mac or PC. And both are available in the iTunes App Store.