A mouse is more comfortable than a laptop trackpad but does depend on a flat surface. The Gyration Air Mouse avoids this with a clever combination of sensors so it can be used in mid-air. It is very small and comes with a pouch. It may not take up too much space in a laptop bag but it is not that comfortable for larger hands. It won't replace a full-size mouse. There is trigger button on the underside to engage the in-air mode. It takes a little getting used to but works better in practice.
