Between email, USB drives, and cloud services like Dropbox and SugarSync, there are plenty of ways to move files around. But sometimes what you really need is to get a file from your desktop to your iPad quickly. Syncing via iTunes is an option, but that process can be slow, especially if you haven't synced your iPad in a while.
Air Sharing ($9.99, iTunes) allows you to mount your iPad on a desktop computer, so you can move files back and forth as if it was a USB flash drive. It works with PCs, Macs and Linux machines, so no matter what your hardware configuration is, Air Sharing makes moving files a snap.
To exchange files, your computer and your iPad need to be on the same Wi-Fi network. Start Air Sharing on your iPad, and click the Network icon at the bottom of the screen. A panel will pop up listing the current addresses for your device.
How you connect will depend on what operating system you're using, and how you want to connect. Macs and PCs running Bonjour can connect to the iPad at youripad.local, where youripad is the name of your device. Air Sharing also reports the current IP address of your iPad, so you can connect that way.
If the concept of connecting to a file server sounds intimidating, don't worry. Tapping the Help icon at the bottom of the window brings up platform-specific instructions for connecting to a server with OS X, Windows, and Linux systems. If you're only moving a few files, the browser interface will work in any modern web browser—all you need to do is type in the address listed in Air Sharing.
Once you have files in Air Sharing, the onboard document viewer lets you open common file types such as PDF and Office documents. You can print files to nearby network printers, save images to your Camera Roll, and send emails with your files attached.
Additionally, Air Sharing is a one-stop shop for your cloud files. You can connect to Dropbox and Google Drive accounts, as well as FTP servers, WebDAV servers and more just by clicking on the Add button and entering your credentials.