Jack focuses on software, but there are other techniques. A pullup resistor with a capacitor works well (preferably followed by a schmitt trigger) for slow responses although you should be aware that when you close the switch a short spike of high current will flow through the switch. You can limit that with a small series resistor. A cross coupled NAND or NOR gate combination will work if you have a changeover switch. Also if you use a non-inverting buffer (like 2 x 74HC04 in series or a MC14050) and connect the output to the input by a 10K resistor and also use a changeover switch you will have a debounced output.
Other manufacturers also make debounce chips. Maxom does the MAX812 and several others. See this app note.
Hi Steve -- this looks like an amazing project -- I hope one day to see it with my own eyes -- with regard to the links to interesting sites and videos, I have to say that I love the christmas tree one -- wow!