Train your cat to obey respect speakers. It's not as hard as you might think. Out of all the suggestions the spray bottle of water worked for me. Only had to do it a couple times. After that my cat lost interest except for listening purposes:
http://cgim.audiogon.com/i/vs/s/f/1242581289.jpg
http://cgim.audiogon.com/i/vs/s/f/1242581289.jpg