It seems that each Ajax History and Bookmark plugin has some minor bugs, ranging from
Really Simple History
http://code.google.com/p/reallysimplehistory/
jQuery History plugin
http://www.mikage.to/jquery/history/rbbs.cgi?id=RA12733222240679954806&focus=1
Ajaxify
http://max.jsrhost.com/ajaxify/
The bug is either not firing off the event at all, thus the content is not changed, or the event is fired off twice (better than not firing off at all). Is there an Ajax History and Bookmark plugin that work in all modern browsers? (IE 7+, Chrome, Firefox, Safari)
jQuery History plugin seems to be best except it has this bug:
Toggling between 2 bookmarks (or see a page, and load another page from bookmark) won't work with jQuery History plugin
Another vote for jQuery address. Super simple to use.