You've heard of SATA. It's the technology used for the majority of today's hard drives and people generally like it. But SATA wasn't designed for tiny portables. That's why the guys behind SATA are introducing mini-SATA, or mSATA for short.
Supporting 1.5 Gb/s and 3.0 Gb/s transfer rates (peaking at half the speed of existing SATA), mSATA is intended for drives that are roughly the size of a business card.
Check out that lead shot. On the left, you see a small Toshiba drive using a traditional SATA connector. On the right, you see a Toshiba drive using the mSATA standard. (Incidentally, Toshiba will be offering that flash drive in 30 and 62GB sizes with 180MB/s read speeds and 50MB/s writes.) The end products aren't really so different in terms of size, but the mSATA connection itself is, what, half the footprint of SATA?