Just a quick note that I just finished installing a wireless keyboard and mouse, and everything works great right out of the box :) :) All I had to do was turn off my computer, unplug my old monster of keybaord + mouse, plug in a Logitech gadget (some technical term huh?) into a usb port, and turn my computer back on. This is the easiest hardware installation I have ever encountered. I don't mean this to be an advertisement for Logitech, but you have to given them a lot of credit for making their stuff so easy for non-technical people to install.
I've used Logitech mice almost as long as they've been making them, and have found them to be easy to use, very reliable. As long as you're mating current products in current OS's, they do work very well out of the box. They have a lot of configurable controls - you really can "Have it your way!"
Right now I've got three of their wireless keyboard/mouse sets. This one on my main home machine dates back to about 2000, and still works fine in XP.
Once you go cordless, you'll probably never want to go back to wired inputs again!
only problem I've encountered with logitech wireless KB/ mice is with the bluetooth mx5000 set, it tends to freeze every 4-5 hours for about 10 seconds and then everything is good for another few hours based on this happening about 2 times every workday to me.
To be fair there are about 10 - 12 other KB sets in the area that could be interfering and apparently if you install the software it works seamlessly. Seeing as how this KB is on a Linux box I have no access to the windows only driver, and no I don't want to install wine :)
The battery life is good, 3-4 months on 4AA batteries for the KB and recharge stands for the mouse which goes about two weeks on a charge.