The interfaces allow users to operate the devices using a thumb on one hand. The interfaces target screens from 2 to 5 inches, measured diagonally, with resolutions ranging from 176 x 220 to 800 x 600 pixels.

The researchers detailed the two different interface approaches in a technical paper delivered at this week's Conference on Human Factors in Computing Systems in Portland, Ore.

The AppLens interface uses a tabular fish-eye approach to provide integrated access to and notification for nine applications. The second, called LaunchTile, uses pure zooming within a landscape of 36 applications to accomplish the same goals.

In their paper, the researchers detailed thumb-as-stylus designs that allow users to operate hand-held devices using only one hand. Although existing stylus-based gesture systems do not preclude the use of the thumb, no systems have been specifically designed to be operated using the thumb, according to the researchers.

Microsoft Research is making a big splash at the 2005 ACM SIGCHI Conference with more than 30 researchers from the company's Beijing, Cambridge, U.K. and Redmond, Wash., labs delivering 22 papers, or 10 percent of the papers accepted. Microsoft's focus is information visualization, and the papers are the result of collaboration with more than 16 universities and several corporations.

"Information visualization is a hot topic today because computer system and graphics capabilities have reached a point where the visual representation of information can come to life," said George Robertson, senior researcher at Microsoft Research.

Microsoft Research employs more than 700 engineers at six labs in Redmond, Cambridge and Beijing along with labs in California and Bangalore, India.

The 23rd annual CHI conference is sponsored by the Association for Computing Machinery's Special Interest Group on Computer-Human Interactions.