From Nokia Developer Wiki
This article addresses the design of usable touch-screen interaction. With the recent release of several touch-screen models, this issue is particularly topical and relevant for developers hoping to target touch-screen Nokia devices. The article highlights several of the key issues that designers need to consider when designing for touch-screen devices. In particular, designers need to make sure that user interface controls are as easy to select as possible in order to prevent errors and user frustration. Input also needs to be as simple as possible, as repeated input on touch-screen devices using awkward interaction controls can lead to user frustration. The article is simple, yet provides several important tips for touch-screen design.
The following link provides some useful information on the pros and cons of designing for touch-screen interaction: SAP Design Guild