I have used wireless keyboard & mouse combo units and found that they are totally unreliable. The thumb stick is nearly useless in precision and doesn't allow you to quickly move the mouse around the screen. They also tend to run through batteries quickly, and when running low on batteries they will miss key presses or mouse input randomly. I searched for a wired keyboard & mouse combo and found that my options were very limited. Many of them were built for media center PCs and have non-standard keyboard layouts, small keys, and were also pretty expensive.
After running out of other options, I decided to roll my own! This instructable will show you how to take an ordinary USB keyboard and USB trackball mouse and combine them into a single unit. The units in this instructable are WIRED, however you should be able to do the same thing with a wireless keyboard and mouse, albeit at a much higher price.
Step 1: Gather the materials...
1) LITE-ON Black USB keyboard - $7
2) Logitech Gray 3 Buttons + Wheel USB TrackBall TrackMan Wheel Mouse - $30
3) SYBA 4-port mini USB hub - $8
4) BYTECC 10ft USB extension cable (Type-A Male-Female) - $3
5) JB Weld - Had this already.. use whatever epoxy-like compound you have handy
6) Small Zip Ties - Already had this as well, feel free to use twist ties or whatever
Total price: $48 + shipping
Total time spent: ~30 minutes construction time, plus a few hours to let the JB weld set properly
Step 2: Pop the number pad keys off
Take a flat-head screw driver or other flat instrument (butter knife?) and pry all of the keys off of the keyboard. I say it is exciting because these little keys just FLY OFF and across the room! Watch your eyes here, really!
I also recommend doing a dry-run before hand to make sure your mouse is going to fit in the proper location.
Step 3: Create JB Weld tools & mix JB Weld
Once your tools are finished, use the plastic mouse shell that came in the packaging as a good place to put your JB Weld / epoxy, and mix up a small batch!
Step 4: Attach mouse to keyboard
I would highly recommend laying down some plastic wrap or a pizza box or something down when doing this step, you really don't want to get JB weld stuck to anything unintended.
Be sure to wipe off anything that you accidentally epoxy as soon as possible, once its dried its a horrible mess to get off!
Once you're happy with the JB weld job, set the keyboard down somewhere flat so the mouse doesn't slide off, and get the location of the mouse however you like it. I recommend sitting the keyboard on your lap and type on it a bit, and make sure that the mouse feels right, because once it's dry its not going anywhere. Luckily, JB weld takes a while to dry, so you have half an hour or so to play around with it.
Step 5: Finishing up
This is the time to also hook up your USB hub, and then use the extension cable to connect it to your PC. Since you're using an active hub, the length of your USB cable can be up to 16 feet without having to go to an active-repeater-cable.
Give the keyboard a few hours to dry before you start trying to really use it. JB Weld is very slow to dry, so leave it over night. If you use a 'real' epoxy, it will certainly dry much faster.
Once you give it time to dry, its very strong, I am able to lift up the keyboard by the mouse with no problem. I've been using it for a week now and it works AWESOME! Watching movies is much more pleasant now! :)