USB External Drive Solutions

Question

USB solutions for MacBook Air:
USB port powered SSD or thumb drives with minimal power requirements seem a good fit.
A USB external hard drive with extraordinarily low power requirements would be another option; possibly one of the green drives might get away with using just USB bus power? Most hard drives do require AC power to safely work with a USB connection. It would be great to determine which if any external hard drives can operate using the minimal current provided through the USB port but I suspect that specific goal will be limited to external flash drives.
Would love to have an external SSD drive with substantial capacity which operates solely on USB power. One nice feature on a cost basis is that it would not need to be especially fast since the bus itself is so limited, so it seems reasonable that there is a scramble going on as I type by vendors seeking to fill this price sensitive niche for all the new Air owners. A relatively slow form of SSD drive would suffice, even something along the lines of a large capacity ordinary thumb drive might be good since the USB bus itself is so limited in speed.
My goal would be something fast enough to saturate all the speed the USB 2 port is capable of, which renders most of the slower ordinary USB thumb drives "not good enough".
Some of the latest USB 3 capable thumb drives might be just the ticket; maybe even several small ones. I can see having one on each side of the Air (balanced with care!). A small flexible dongle would be good in this regard because it could cause serious damage to have a thumb drive's leverage cranking on the USB port of such a thin light device.
Ideally the storage devices would be of the 128 Gb or larger range so as to be able to fit things like Aperture and iTunes libraries.
Of course they will be slow with the Air but they will be portable and functional in a pinch. There would still be speed where it would be needed most, which would be updating that type of database from one's main machine, since the use on the Air would for many of us be modest access to the data.
So you'd have a device which is fast to sync up from your main machine, and as fast and light and nimble as possible for use with the Air on the road where no power is available.

Answer 1

One of the enclosures which feature USB2 and FireWire 800 ports would be great, but many of the ones I am seeing seem to be larger than the USB only models. Of course there's more going on inside those cases that also have FireWire on their boards, but if there's a super slim one out there somewhere that would be cool to know about. This new 750 Gb 7200 RPM drive in a case that can use the speed would be interesting:
http://www.hitachigst.com/internal-drives/mobile/travelstar/travelstar-7k750
The new 320 Gb 7mm drive is also compelling for it's minimal size and the fact that it's a 7200 RPM model too, but of course it has less capacity. It will be interesting to see if it has less drain on the battery; in that regard, a single platter slower spindle speed drive would have the most advantage in theory but this one brings speed and a lighter thinner single platter design to the table so it's pretty interesting. In a form fitted super slim case it would be nifty
http://www.hitachigst.com/internal-drives/mobile/travelstar/travelstar-z5k320
Goal: obtain the fastest speed from a desktop Mac or MacBook Pro with FireWire 800 to the drive, then using the drive via USB with the Air with minimal power draw and a small physical size. I'm certainly not alone in this desire, the sheer lack of size of the 11" Air is such a game changer that smaller add ons become that much more compelling for maximum mobility.
It's like the first time I used a Duo, or the 1400, or the 2400, or the 12" PowerBook, only a LOT better! I've used almost every model over the years and dismantled them all too, my first PowerBook was almost 20 years ago. Been using the 11" non stop for 2 days now and I still bust out laughing every time I fire it up.