USB 3.0 is fast. Faster than standard 7200 RPM disks can handle. So how do you make external storage faster to better fill up the transfer pipe? By putting an SSD inside.
As expected, these USB 3.0 SSDs are both costly and small, compared to your normal USB 3.0 disks. You're getting a 1.8-inch drive in 64GB, 128GB and 256GB sizes for $230, $400 and $850, respectively. Normal folks that only need external backup of their photos and music for traveling on the road will want to stick with non-SSD type drives, but pros and people who need fast drives to supplement their laptops will find these useful. And at 1.8 inches, they're about phone-sized and can fit nicely into pockets.
All three drives will be released in early November. Iomega tells me that these SSDs are about twice as fast as 7200RPM USB 3.0 drives, and 10 times as fast as USB 2.0 drives. [Iomega]