What do you need from a cordless keyboard? Basically, no cord, and keys that work. Things like smooth action, well-spaced keys, special-function Internet controls and a weighty feel that stops it sliding around are all pluses. The Mitsubishi Diamond Touch DTRF-1 has all these things, so it gets a 'high' usability rating.
Add a decent, if not spectacular, scrolling optical mouse to the radio-driven package that gives up to two metres freedom to roam from the receiver unit and it's a winner at $144.95.
Other good points are the simple one-touch radio setup and synchronising, the groovy flashing status LED on the USB-connected receiver, and the nicely contoured and reassuringly solid mouse. A less attractive aspect is the (admittedly extremely straightforward) setup that hijacks your email client and imposes Outlook as default mail software with no option to set up an alternative, which is just sloppy.
The mouse also suffers from a slightly jerky action, which is not entirely unusual for RF mice. This shouldn't interfere with normal operation, but can be a minor annoyance for some.
The other controls for Explorer, Search, Favourites and volume all work seamlessly, and are uncomplicated enough to be useful (unlike some do-it-all keyboards we have seen).