I am disappointed that Mac World has never,to my knowledge, evaluated keyboard models that have a built in trackball, touch pad or force sensitive cursor pad when you have done reviews on keyboards. Is this an oversight on your part or is it by choice?
I know of at least six models. Such as the Belkin MediaPilot, several offered by Adesso etc. For further information on keyboard with built in mice features the following website carries several models and may help answer questions should anyone wish to proceed further. (P.S. they are listed as windows compatible, but they work fine on our MACs (17 PowerBook, Mac Mini & iMac Pro Duro).
http://www.fentek-ind.com/wireless.htm - kbmwwtb
We have tried several different models, our favorite and one that we have been using for the past two years has as trackball. Marketed by Fentek model KBMWWTBU, they now have a newer model with more features and works with RF instead of infra red.
Having both the keyboard and mouse incorporated together as one unit has several advantages and increased flexibility. The main one being that you can use the keyboard on your lap without needing a desk near by. We have a Mac Mini in our living room connected to a 55 rear screen TV. We can edit iMovies, check email from across the room, with the keyboard in our lap. Having a separate mouse would be awkward requiring keeping track of two pieces of equipment and the additional need to have handy a flat surface near by to have the mouse to work optimally. This same reasons goes for PowerBooks as well.
Now with the push for making computers a multi media living room appliance (iTV or what ever) having a mouse feature built into a keyboard will be needed more than ever.
I sure would like to see future articles cover these type of keyboards.
P.S. When comparing between RF and infra-red devices, RF is better if the keyboard and the computer is some distance from each other because the infra red receiver needs to be located in a key location (line of sight transmission) and also people/pets passing by can interrupt the signal too.