This extension works for most URL's.
However, this does not work for search URL's which remain
index.php?route=product/search&search=.
Also the product tags are converted into invalid URL's. They are converted from
index.php?route=product/search&tag= to
product/search&tag=, when they should be converted to
product/search?tag=. If a single query is within the URL, then a question mark should be present not an ampersand.
Jay Gilford hinted towards this here in the comments:
http://stackoverflow.com/a/10902883 but did not elaborate to provide a solution. Would anyone know how to fix this?