Twilio-grooveshark is a project mainly written in JavaScript, it's free.
Control Grooveshark via text message
npm install connect express socket.io twilio
Download the latest release and unpack the source code onto your server
Open server.js and bookmarklet.js and enter your domain name, port number, twilio account info
Log into Grooveshark and run the bookmarklet (substitute your domain name and port):
javascript:(function(){if('undefined'==(typeof window.twshark)){document.body.appendChild(document.createElement('script')).src='http://mydomain.com:4444/bookmarklet.js?_='+new%20Date().getTime()}})();
Text a song name to add the song to the queue or next/prev to move through the queue.