I've just written my second Chrome extension. This one adds a context menu to allow Readability to be triggered automatically for the current website. It works best with the Readability Redux extension, but will work (although slower) without it.
Version one is a bit hamfisted - it works for any URL within the top level domain, but the next version will add support for controlling the list of URLs and use of wildcards to make it more flexible.
Get it here: Permanent Readability.