I can understand people's frustration when the hashbang feature breaks the URL function in the browsers, but it can work nicely if done right. I've built one of my apps using hashbang to encode the browsing state, and had gone to great length to ensure bookmarking and back button work correctly in the browsers.

It works great at the end. Every URL points to a specific page and still gets the Javascript interactivity. Some sample URLs.

http://www.previouslook.com/hnews/new#!2011-03-01-15-15.22

http://www.previouslook.com/hnews/new#!2011-03-01-12-15.15

http://www.previouslook.com/hnews/new#!2011-03-01-12-45.12