I can run your code without errors with the last version of the stand alone server and the selenium python bindings (2.31 at the moment).
I usually start the server in background:
java -jar selenium-server-standalone-2.31.0.jar &
Then starting from version 2 of the python bindings your can use the simpler:
import selenium.webdriver as webdriver
driver = webdriver.Remote(desired_capabilities=webdriver.DesiredCapabilities.HTMLUNITWITHJS)
driver.get("http://www.google.com")
Just make sure the background server is actually running, test it by opening a browser and typing the url
http://127.0.0.1:4444/wd/hub/static/resource/hub.html
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