Whether sitting in an aircraft, tram, taxi or train, the notebook computer user needs a certain degree of control if there is work to be done. The most important part of the graphical user interface (GUI) that is common to operating systems for personal computers is the way the cursor is moved. Infra-red devices have been developed, such as Singapore's IPC with its three-dimensional mouse that clips on to the index finger. Touch-screen devices are available, with certain models of notebooks activated to accept controls from a pencil tip or fingertip hovering on the screen surface. However, these options are impractical for many notebook computers because the finger mouse is too cumbersome for a mobile operator and oily fingerprints on an LCD detract from screen visibility. There are keyboard shortcuts for various operating systems, but it is the mouse or the mouse replacement for the notebook PC that gives the GUI the best chance to live up to its reputation as easy to use. Choices are proliferating, and sometimes that makes it harder to decide how to point your notebook cursor. The best mouse is usually the one that most suits a user's needs.