Awasu 1.1.1 introduced support for submitting SOAP requests to web services and transforming the results into RSS using XSLT. One of the things that these features let you do is monitor a Google query using Awasu. Sample files are provided along with instructions on how to set things up.
This plugin takes care of setting the necessary files up and configuring them, making the whole process a lot easier. All you have to do is enter the query you want to monitor and it will take care of everything else.
IMPORTANT: You need Awasu 1.1.1 to use this plugin.