Possible Duplicate:
What's the shebang (#!) in Facebook and new Twitter URLs for?
Hello!
What is the difference between this URL: mysite.com/images.php#img-1 and this URL: mysite.com/images.php#!img-1, please?
I have a simple photo gallery, nothing fancy, that changes images from a JavaScript array of files and instead of refreshing the page for every image it does it "on the spot" using jQuery.
Thank you.
It is for "Ajax Crawling"
If you're running an AJAX application with content that you'd like to appear in search results, we have a new process that, when implemented, can help Google (and potentially other search engines) crawl and index your content. Historically, AJAX applications have been difficult for search engines to process because AJAX content is produced dynamically by the browser and thus not visible to crawlers. While there are existing methods for dealing with this problem, they involve regular manual maintenance to keep the content up-to-date.
and
- Indicate to the crawler that your site supports the AJAX crawling scheme
The first step to getting your AJAX site indexed is to indicate to the crawler that your site supports the AJAX crawling scheme. The way to do this is to use a special token in your hash fragments (that is, everything after the # sign in a URL): hash fragments have to begin with an exclamation mark. For example, if your AJAX app contains a URL like this:
As soon as you use the hashbang in a URL, Google will spot that you're following their protocol, and interpret your URLs in a special way - they'll take everything after the hashbang, and pass it to the site as a URL parameter instead. The name they use for the parameter is: _escaped_fragment_
reference: http://www.seomoz.org/blog/how-to-allow-google-to-crawl-ajax-content
