I've been using an AirStash (US$99.99) for about a week and have grown to like it very much. This tidy little device stores movies, music, documents and photos for portable, wireless sharing between iPhones and iPads. It allows you to stream those files via its own Wi-Fi network and share with colleagues, family and so on, all while saving space on your iDevices. In my experience it was easy to use and even passed the "keep my kids entertained during long road trip" test, which is crucial. Here's my look at the AirStash for iPhone and iPad.
Design
