"We're approaching an era of ubiquitous computing, where computers will be on almost every device. Some of these will be too small for a keyboard," says Xuedong Huang, manager of the speech technology group at Microsoft Research.

The research group has developed the first prototype to use Tap and Talk technology, the MiPad (multimodal interactive pad), a palm-sized device that is a combined cellular phone, pager and hand-held computer. MiPad grew out of a project known as Dr Who (for work, home and office), which is developing a series of technologies for portable computing.

The MiPad has a built-in microphone, which is activated whenever a field is tapped. The speech recognition system, Whisper, has a 64,000-word dictionary, and recognises natural or continuous speech. Users "train" the MiPad to recognise their speech by speaking into the built-in microphone for 30 minutes - Dr Huang recommends reading a book.

The device also uses a spoken-language understanding engine, which understands context. For example, when the user calls up the contact list and says, "Meet Mark East on Friday at four", the Mipad understands that the user means this coming Friday at 4pm and not in the early morning.

Putting speech technology on a portable device is no gimmick, according to Dr Huang. "Using speech to enter data is twice as slow as using a full-size computer keyboard, but it is five times faster than using the miniature keyboards found on hand-held computers," he says.

MiPad has most of the features used by personal information management systems, including an address book, contact list, receiving e-mail and address book, but Microsoft has no firm date for when devices such as MiPad will reach the market. So it remains to be seen whether the term "tap and talk" will become as ubiquitous in the PC world as the phrase "cut and paste". http://research.microsoft.com/stg/xdh