Hotmail

The original Hotmail was a stroke of genius. By bringing desktop software to the web (and becoming a huge hit in the process), Hotmail effectively ushered in the web 2.0 world of online applications - think Google Docs, Google Maps, Google Calendar, Flickr and so on.

These days Hotmail is owned by Microsoft (and part of the Windows Live suite). It's rather ironic when you consider that the very online applications Hotmail spawned are making the software giant's cash cows - operating systems and office software - look increasingly anachronistic. Why pay for programs when you can get them online for free?

TiVo

If you told your Gran you were going to replace her old video recorder with a stripped down computer, she'd beat you senseless with her walking stick. But if you gave her a Sky+ box, she'd give you a cup of tea and maybe even some biscuits. It's an absolute doddle to use and it's in more living rooms than media PCs can ever dream of reaching.

But there's an argument that, without TiVo, there'd be no Sky+ at all. BSkyB originally partnered with TiVo in the UK, before breaking away to build its own digital video recorder. TiVo was arguably ahead of its time - an HDD-based TV recorder that defined the term 'PVR' and featured a clever thumbs up/thumbs down rating system to learn (and then anticipate) your TV watching tastes. While TiVo has been popular enough to attain 'verb status' in the US (i.e. "I TiVo'd it last night"), its failure here is one of the sadder tech tales of recent years.

CCD

The Charged Coupled Display, or CCD for short, is the eye of a digital camera - and it's older than you might think. AT&T Labs built the first CCD in 1969, but it wasn't until 1975 that Eastman Kodak's Steven Sasson created the first digital camera. It had a 0.01 megapixel resolution and took 23 seconds to capture an image.

iRobot Roomba

People have been trying to flog us robots for ages, but the iRobot Roomba stands out for two reasons: it isn't threateningly expensive, and it won't scare the dog (or pretend to be a dog, like Sony's now-canned AIBO). It turns out that successful robots aren't do-everything humanoids or plastic pets. Instead, they're simple little gadgets that do one thing and do it well. With the Roomba that thing is hoovering. But the firm also makes robots that can do the guttering, wash the floors, clear up the garage or pull the limbs off your enemies. We made that last one up.

PageRank

Developed by Larry Page and Sergey Brin while still at university, PageRank went on to become a website called Google. You may have heard of it. Unlike other search engines, which simply scanned the content of pages, PageRank looked at incoming links too - rightly assuming that a site with loads of incoming links from reputable websites is likely to be reputable too. The rest is - ahem - search history.

The vibrator

Invented in the 1880s to cure "female hysteria", the vibrator has certainly made a lot of women feel better - although not, perhaps, in the way its inventors intended. The combination of the vibrator and The Pill has transformed attitudes towards female sexuality, with the former making the odd bloke feel inadequate in the process. Before today's more open attitudes to sex, and despite clearly being designed for other parts of the body, vibrators were often advertised as neck massagers. You're doing it wrong!

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