Jakob Nielsen on mobile usability: Utilize Available Screen Space

Jakob Nielsen's Alertbox article, "Utilize Available Screen Space", outlines findings from iPad usability studies:

• higher information density designs are preferred because they minimise scrolling and pop-ups;
• but don't cram too information much in a small space, otherwise users will be overwhelmed; 
• avoid small interaction widgets because they are hard to use;
• keep things as large as possible.