Best Ajax Search/Filter

I am looking for the best way to mimic the facebook friend window, where you can use ajax to filter what you type and update it.

Any suggestions? I was playing with flexgrid but I think that's overkill

From stackoverflow

• I think this is what your looking for:

  I've had some success using this in an app: http://bassistance.de/jquery-plugins/jquery-plugin-autocomplete/