The PHD's size and ease of connectivity are shared with USB Flash drives, of course. What sets the Seagate product apart is the excellent, easy to use software that it's supplied with. The PHD toolkit clearly displays how much free space is left on the disk. It allows you to make the drive bootable, and you can also repartition the disk here, although any data resident at the time will be lost.
Next up from Seagate we have the 100Gb USB 2.0 Portable Hard Drive. This device is a small (2.5") hard drive packed inside a strong shell. Its specifications are as follows:
-2MB cache (40GB)
-8MB cache (100GB)
-5,000 Gs nonoperating shock resistance
-Whisper quiet: less than 23 acoustic decibels
-Horizontal dimensions: 1" Deep; 3.7" wide by 5" high
-Weight: 10.3 oz (~300 grams)