It's hard being a hard disk maker. You make things bigger and bigger and bigger, and people say: 'Oh, 30GB is plenty.' So they search desperately for things to do with PCs; things that really, really chew up the disk space.

This has two effects. The obvious one is that people start creating video software. The less obvious one is that the makers of expensive disks start complaining. The expensive disk business isn't what it might seem.

You can still hear people proclaiming the glory of the 15,000rpm SCSI disk. Among these enthusiasts you will find HP, maker of the eye-wateringly costly Proliant range, not to mention the nut-tighteningly expensive Blade servers.

'It's all nonsense,' is what the mavericks say. And one of those mavericks is Jim Gray, one of Microsoft's senior researchers (and known as 'the father of transactional processing') from San Francisco.

"I'm getting into a lot of trouble," he confessed when I met him in Amsterdam at Microsoft's TechEd forum. "I keep saying that I don't need these disks. I also keep arguing that storage area networks are not a good thing."

It's not as if Jim is playing with small laptops. His project at the moment is the WorldWide Telescope, a globally distributed database with simply vast amounts of storage.

"We had a $2m system," he explained. "A lovely system from Compaq, now HP. We've replaced it with a no-name PC, which we mirror and, because we're paranoid, we mirror it again, so we have three systems, with petabytes of storage. It costs $120,000."

And it uses plain old 200GB 7,200rpm Seagate disks, of the sort that are only supposed to be used for digital video recorders, costing around $200 per disk.

"And people say to us: 'You have got to have good solid SCSI San systems with good solid reliable hardware.' And, in fact, we have not had a single failure since we built this no-name system," said Jim.

Back to video. I think I've found a way of forcing people like me to upgrade their disks. It's called OneNote and is designed for Tablet PCs. It works well with Tablets because it uses digital ink, but it works just as well on a notebook.

Here's the trick: say you're taking notes of a meeting for the minutes. You can probably keep up with some of it, until you have to start contributing. Five minutes of heated argument later, you realise that you haven't noted a word.

OneNote lets you record audio at the same time as you type. Well, any tape recorder can do that. What makes OneNote special is that if you click on your typed notes later, it starts playing back the audio that was recorded at that point.

So you can just type the name of who was speaking, and a two or three word summary. 'Jim: cats are fierce. Brenda: the garden needs digging. Tim: how to clean a duck.' And so on.

The thing is, nobody's interested in duck-cleaning. So when you transcribe the notes, you can ignore it without having to listen to the whole recording to see when the duck bit starts and finishes.

How many thousands of meetings could you minute on a 10GB disk? At full CD quality? 'Pah' (said the vicar), 'I could fit that on my iPod.' So Microsoft upgraded OneNote to record video. Take the webcam with you and you get lip-synch as well as voice-synch for your recordings.

Yes, of course it will chew up disk space. Buy a new 200GB Seagate for £150, stick it in a USB 2.0 enclosure, and what do you care?