Touch computing is one of those eternal promises in technology. The idea has been around since at least the 1980s, but has rarely showed up in legitimate products. This year, however, new touch computing devices from Dell, HP, Asus and others have shown the true potential of the technology.

Of course, Apple got the ball rolling when it released the iPhone, which supports two-fingered multi-touch gestures. The idea makes sense because, once the software has been fine-tuned, you simply use your fingers to control the device.

Microsoft has followed suit with technologies like Surface, and has decided to make touch one of the cornerstones of Windows 7. And of the future? When ubiquitous computing finally arrives – the idea that your bathroom mirror or a wall in your entryway will hold a computer display – touch will be the only viable input method.

"The opportunity for PCs is to play a role in less traditional environments, such as kiosks and booths where the PC powers larger multi-touch displays," says Agnieszka Girling, director of project strategy at Artefact, a company that works on next-generation computer interfaces. "This reduces the cost of creating such displays by eliminating the need to develop proprietary technologies to do so."

Here, rather than covering prototypes or products that may never be released, we have tested existing products to see how the touch interfaces work, how the screens respond to touch, and if the devices will actually help you in your daily work.

HP TouchSmart TX2

HP is one of the leading companies in the world of touch computing. Having done its homework at HP Labs in India on touch interfaces, it has discovered that people in different parts of the world have a 'touch language' and will, in some countries, drag out with their fingers to zoom in, instead of the more natural UK and US action of dragging in to zoom.

The Misto Coffee Table PC (which HP unveiled in 2006) and the HP Obscura Multi-Touch Video Wall (showcased at the D5 conference in 2007) were early examples of HP touch computing. Last year, the company released the TouchSmart IQ506 all-in-one desktop, and now it has taken that touch interface and put it into its first touch laptop, the TouchSmart TX2.

In a hands-on test, the first thing we noticed is that the multi-touch screen acts a bit like a single touchscreen. Meaning that even though the screen itself supports gestures, you generally just click on options on the screen to use them.

The one place where you can use two fingers is the main interface screen, where you can adjust the size of the thumbnails using a click and drag movement. You can also zoom in on photos easily enough, and to browse a website you can just flick up or down.

We would have preferred a few extra controls, such as the click and rotate gesture on the Dell Latitude XT2. However, the good news here is that HP has continued to tweak the touch software included on this laptop and the desktop line and may add more gestures in the coming year.

Some of the controls we'd like to see include a way to minimise a window (maybe it's a diagonal swipe) and a better paint program that supports more pen sizes and brushes.

Another interesting perk for TouchSmart TX2 users is that developers are starting to release new apps. They are available at the TouchSmart community, along with the support forums and news.

Now, to be clear: the TX2 is a Windows Vista laptop that, for the most part, runs Vista applications. The HP TouchSmart interface runs as another application for Vista. Within that HP interface, you can run touch-enabled apps, such as a YouTube viewer and a nifty kitchen egg-timer app.

It's great to see these extensions of the touch interface – the same community support for touch interfaces is starting to happen with the Windows 7 Public Beta as well, as developers are starting to create touch apps for the upcoming OS. Unfortunately, Windows 7 does not yet run on HP TouchSmart computers because, according to HP, the company does not release drivers for Beta software.