I have the Gyration mouse/keyboard combo, and while they are really nice, there is no on/off button, so if something accidently falls on the keyboard, it will waste the batteries pretty fast. I am actually looking for something to replace this setup, am thinking about one of those flexible/rollable keyboards such as these:
http://www.thenerds.net/productpage.asp?un=299233&s=1
They should be easy to hide.