I would like to develop a website with fully ajax navigation, but this means that users cannot share, bookmark, or go straight to certain content.
I noticed a few websites (Gmail, Thesixtyone, Youtube) are using hash tags to create custom urls for different page configurations. What is this technique called, and how can I implement this?
Loon into JQuery address. http://www.asual.com/jquery/address/
This does exactly what you're talking about. However, since you asked what the # means in custom URLs, I assume you're fairly new at this. JQuery address will look intimidating at first, but it's really quite easy. You should use JQuery for all your ajax handling too.
# is an anchor tag. if you do this <a name="list">This is an anchor tag</a> then add #list to the url, the page will jump to the a tag where name = list.