Such an arrangement would be clumsy with the current MacBook and MacBook Pro, but could be very attractive if the anticipated ultra-portable model does arrive.

The arrangement, described in US patent application 20080002350, is in some ways reminiscent of the old PowerBook Duo and DuoDock. It would help provide the best of both worlds - a small and light notebook when mobility is important, and a large screen and separate keyboard plus extra peripherals on the desktop. And since it's the same computer, there's no need to mess around with file synchronisation and related chores.

The details of Apple's design include mechanisms for carrying away the heat generated by the notebook, wireless data links between the notebook and the docking station, the use of induction to provide power to the notebook without the need for an electrical connection, and provision for the notebook to provide power to the docking station.

Such arrangements would reduce the need for exact alignment, as well as minimising the wear and tear suffered each time the notebook is inserted or removed. The use of magnetically-coupling connectors would also help in this regard.

As usual, the application is couched in broad terms to provide maximum coverage, and it is unlikely that every possibility will be embodied in actual products. For example, the application canvasses the possibility of using either standard connectors (eg, external monitor and power connectors) to link the two units, or a proprietary connector.

Similarly, the notebook might protrude from the side of the docking station so that it may be easily removed, or the station could contain an ejection mechanism.