Could the days of the flash drive already be numbered? That's one conclusion you could draw from Sony's new Micro Vault Pro. Slightly smaller than a cigarette packet, the device is a 2GB portable storage solution that simply plugs into your PC via a USB connection. It gets bonus points for having the USB connection on a rotating arm, to help get it attached in, ahem, 'cluttered environments'.

Within its stylish, brushed silver exterior is a minute hard drive, and that accounts for the jump in capacity over conventional flash drives. It is worth making a minor point here that hard drives contain moving parts, and moving parts are more likely to go wrong than static flash technology, but the risk is relatively minor.

It's also worth noting that just because there is a hard drive in there, that doesn't mean you'll be able to hear it. You do, however, get an LED that indicates when data is being written to and retrieved from the drive.

You also get a software tool bundled in. This is Sony's automatic synchronisation program, and while it's small, it is effective. Basically, on setup you select the folders from your hard drive that you want to synchronise, and then - after performing an initial backup - any changes you make to files within the selected folders are automatically written to the Micro Vault Pro as well (confirmed by a little message bubble that pops up in the bottom right of the screen). The software - which sits happily in your task bar - can also access old files up to ten generations backwards. It worked well throughout our test.

Given the amount of data that's likely to chug to and from the drive, it's not surprising that Sony strongly recommendeds that it's used on machines with USB 2.0 support. That way you can take advantage of the box's claimed transfer speed of 10MB/sec, although our HD Tach test reported a read speed on average of 4.9MB/sec. That's a fair window apart.

Still, there's little doubt that this is a professional, robust and efficient piece of hardware that's as easy to use as it needs to be. Which, sadly, just leaves us with the big downside to discuss - the price. To pick up a 2GB Micro Vault Pro, you're looking at around the £180 mark. That's a ridiculous price for external storage, when you consider that for the same money you can pick up an external hard drive or two (with immensely more capacity), umpteen flash drives, external optical devices, etc.

But then we're in the early days of minute, portable drives, and Sony knows it. This is a premium product for the time being, and one that's destined to remain out of the spending power of most of us for at least another twelve months. When it does become affordable though, it's worthy of consideration.

This is a well made, high quality, portable storage unit, hampered by a price tag that'll rightly make your eyes water.