If you feel like riding the wave (and are made of money), look no further than the newest configuration of Mercury On-The-Go Pro, which is the first that I know of to put a 2.5″ 1TB HDD in a bus-powered enclosure. Sure, there are 1TB units already available (for under a hundy, even), but they use 3.5″ drives, making them bulky and rarely bus-powered. These Mercury ones are the only truly portable terabyte drives out there.
Problem is, they’re not exactly speedsters: 5200RPM means they’re sluggish even for HDDs, and if you want a fast interface you’ll be paying extra. In fact, even just USB will set you back $300, and if you want FireWire 800, you’re looking at an extra $60 on top of that.
It’s the early adopter tax, and I don’t know if it’s worth it when surely WD and Seagate and everyone else have theirs coming down the pipe. Still, I’ve always liked the clear enclosures, and it’s available now. That’s got to be worth something.