Hi Sytse, you list 'Wireless keyboard' but you can also bridge the gap with a wired keyboard by detecting (and amplifying, perhaps even through walls) the clicking sounds (or electromagnetic waves) and crack the code by frequency analysis etc. Using a dvorak, personalized layout or an esoteric language like i do could perhaps partially mitigate such attack. See:

http://www.inf.ed.ac.uk/publications/thesis/online/IM100855....

http://lasecwww.epfl.ch/keyboard/