DiskAID is a simple app that allows you to use your iPod Touch or iPhone as an external storage device. If you're looking for a way to back up files from your computer onto your iPhone or vice-versa, it's a suitable option with a workable interface and a small file size of under four megabytes.

When you start DiskAID, it looks for attached Apple devices and gives you a two-panel display with a list of all of the files currently on your iPhone or iPod. You can select from several buttons to copy files and folders to and from your device, and all of the features seem to work. DiskAID seemed very stable in our tests. It transferred files quickly and recognized our iPhones and iPods in every attempt.

DiskAID's major oversight is its handling of audio and video files. For some reason, the program doesn't read the metadata associated with your media files. Longtime iPhone fans know that Apple devices use a complex and indecipherable system of folders and file names to store media. Without the ability to read metadata, DiskAID is essentially useless for moving media files off of your iPhone or iPod Touch. You'll have to copy your files off of your device and listen to them on your computer to figure out song and video names. Fortunately, the metadata is still there, so you should be able to quickly sort out the confusion by loading the files into a program like iTunes or Windows Media Player.

Overall, DiskAID is a usable but limited application. It's extremely easy to use and doesn't take up much space or computing resources, but the lack of metadata support is disappointing. With that in mind, this is a stable, useful option for iPod and iPhone owners.