Mobile/Car PC systems, custom Micro ATX, Mini ITX, Pico ITX systems. The possibilities are as endless as your imagination. If you can think of a project scenario where the size, electrical requirements, noise levels, and shock resistance of a standard HDD just wouldn't be wise, this might very well be the way to go.
Apart from a few "gotcha's" from a performance standpoint due to the nature of Compact Flash itself, the Addonics ADSAHDCF SATA/CF Adapter makes deployment no more complicated than using a standard HDD, and as such we recommend it. Addonic's could do us all a favor and generate a simple list of Compact Flash devices they recommend for use with the device. If they did, the experience with the product would be about perfect.