I am planning to create a single page, where a user can load his data and manipulate it. It should have a very desktop-like feel (slick driven by ajax).
I evaluated some javascript widget frameworks and decided to try out ExtJS (although any other recommendations would be welcome as long as it supports some sort of a Grid/Table/Cell element this is absolutely a must).

The thing is, that I have never done anything like this before. Most of the time, when I build regular web pages it's just a handful of jQuery calls to load html, send some data, hide/show elements, and I have to say that this feels very clunky and I believe such approach wouldn't yield the best results if I was to keep things this way.

I would really like to see some examples how people build such pages, a repository with an app would be great. I am very interested to see how to communicate between the server/client widgets as seemless as possible. Any pointers appreciated, thanks!