Until very recently, if you wanted a wireless keyboard, mouse, or trackball, you needed to use RF technology. Bluetooth devices have just started shipping, so the majority of wireless peripherals around for the near future are likely to be RF.
RF devices have one big plus to go along with their multiple negatives. The big plus is that they don't (unlike IR) require line-of-sight. The bad news:
Each RF device requires its own receiver, unless you purchase devices (such as Logitech's keyboards and mice) that are particularly engineered to work together.
RF devices don't play well together, so it's recommended that you have only one attached at a time. Receivers and peripherals from different manufacturers may not?and probably will not?work together.
Manufacturers of RF devices recommend that their devices (with a few exceptions) be placed within three feet of their receivers. The receivers themselves need to be at least a foot away from your computer and monitor, and far from AM/FM radios (the further the better).
RF devices often require proprietary drivers, so they aren't just the standard Mac plug-and-play.
Unlike their wired counterparts, RF peripherals need batteries. The receivers are USB powered, but the keyboards and mice are not. Consequently, keep an eye out for the ones with rechargeable batteries?they may cost more to purchase, but not having to frequently replace batteries will pay for itself over time. However, check to make sure that you can replace the rechargeable batteries cheaply, since they will not last forever.
Unlike the limited number of manufacturers of Bluetooth input devices, most of the usual third-party Mac hardware companies make keyboards, mice, and trackballs that work wirelessly via RF. Companies such as Logitech, MacAlly, and Kensington all make wireless variants of their wired devices, generally for just a few dollars more. Figure A-1 shows the Logitech Cordless MX Duo, which allows you to unwire both your keyboard and mouse with a single receiver.
Installation of these peripherals varies from maker to maker, but for the most part they consist of three steps: plug in the receiver to one of your Mac's USB ports (or to a port on an external USB hub), install the accompanying software, and verify that the device can communicate with the receiver. Some manufacturers include multiple channels on their devices so that you can change them if you run into interference: if that's the case, make sure both the device and the receiver are on the same channel.
To get the best results, carefully read any accompanying documentation that may ship with your devices. Common recommendations include not using mice on glass or metal surfaces: use wood or plastic instead.
Keyspan ships their Keyspan Presentation Remote (shown in Figure A-2), which (unlike their Digital Media Remote, mentioned below) works with a small RF receiver to allow you to control your Mac. The KPR is a handy device if you frequently make presentations, and it even includes a laser pointer.
We've had mostly good results with the KPR, but have a one major recommendation if you want to use it: make a small copy of the instructions and put them inside the carrying case. In order to keep the device from getting turned on accidentally and using up the battery, Keyspan made the on/off instructions so convoluted that you'll forget how to turn the remote on if you don't use it regularly. And, speaking from experience, it's unpleasant to be setting up for a presentation session and find that you can't recall how to work your remote.