From Post: liveRequest.js by Jeff Minard
This is the same JS files you've already used in (Real) Live Textile Formating, but I've just changed a few variables (view source to see what changed.)
By modularizing the code, it will be much easier to adapt it to your own website and be able to do "live updates" of all kinds of content! Download the code behind Live Search. (You'll need to cusomize it to actually return results for you though ;)
Live Search: (No "Search" button needed!)