I definitely wanted an accessible keyboard, so I decided I would place one tucked under the control panel. It worked out very well. It remains pretty much out of site when closed, and is easy to get to when needed. It was well worth the little effort needed to install it.

The drawer slides I used were 19" ones I got from Home Depot. First I figured out how tall I needed it to be. I figured 3 inches would be plenty for a keyboard. Next I cut the bottom of the drawer out of some 1/4" paneling and the sides out of some 3/4"x3/4" (1"x2"x3' wood cut in half lengthwise). Then I attached the slide sides to the sides of the drawer and figured out where inside the cabinet the other halves of the slides attach to the wall.

Then cut out and attach the drawer front out of the 1/4" paneling. This is probably a really crappy explanation but its just something you have to think about to your particular project anyways. 80% of getting something done right is just thinking about it first. Here's a pic of the installed drawer...