Every month sees the release of a better and faster cell phone, tablet computer, or laptop. Suitable activities on the limited screen size of a smartphone include reference applications designed for phones, such as electronic pharmacopoeia, and applications for charge capture, limited note-taking, and email. Lightweight forms of decision support, such as medical calculators, opiate dose-equivalent converters, and drug-drug interaction checkers are widely used. Large data entry tasks such as clinical documentation or full-scale order writing are not yet realistic on these devices. Clinical information systems vendors are increasingly offering stripped-down user interfaces for small devices.