Using the latest Chrome Beta (11.0.696.16 beta) and the new HTML5 Speech Input features, we can jump into the future with Wolfram|Alpha.
Make a bookmark with the code below as the source.
javascript:(function(){javascript:input=$('input');
['','webkit','x-webkit-'].map(function(prefix){input.attr(prefix+'speech','').bind(prefix+'speechchange',
function(e){$('form:first').submit()})})})();
Navigate to Wolfram|Alpha, click the bookmark.