When I switch to another controller do I really have to rebuild every part on the page?

[eluser]Edemilson Lima[/eluser]

2) use javascript and ajax calls to load your data dynamically (no need to redirect the browser), then you can say you use web 2.0.

That was my first idea when I started to play with AJAX. But, as nothing is perfect, the Search Engines do not execute Javascript code. If you load data using JS, it will be invisible to SE bots and the contents of your web site will not be indexed on them.