Zoomable user interfaces ZUIs (Zoomable User Interfaces) are a developing technology designed to make best use of small screens such as those on mobile phones or PDAs. They allow you to see an overview of everything you have available, then zoom in to concentrate on the details. The idea is that with so much info now being packed into mobile devices, it has already become difficult to manage it efficiently. ZUIs offer a more convenient and intuitive way of managing the mountain of data available on modern mobile devices, while still retaining a relatively small screen. They're easier to use than scrolling through huge lists and make it easier to keep track of which part of a particular database you're in. They're not a particularly new idea, but the relatively large size of PC screens has meant there hasn't been much of an economic imperative for them until now. Several specific ZUIs have already been developed, including a diary application that allows you to view a whole month, then zoom in on a single day, with the rest of the month displayed in miniature form around the edge of the screen. Another is the PhotoMesa photo archive, which allows you to see a range of thumbnail images, then enlarge one, while keeping the others in view.

They could become invaluable for helping us organise the increasing amounts of data on our mobiles. You could view everything that's on your device on one screen, without the need to scroll through menus. It could also become essential for internet or WAP browsing on mobile devices, making it much easier to keep track of where you are in a site by keeping past pages in view while you browse. Some ZUI applications are already available for Pocket PCs. Windsor Interfaces' DateLens and PhotoMesa are available from www.windsorinterfaces.com. Other interfaces using Java are under development and will start popping up everywhere soon.