Complete website on client side?

Javascript became very popular these days. There are countless frameworks and plugins developed to make our web developer life easier. But... I have a question.

What are the limits of Javascript? Can we make a complete website to work only on client side?

I'm developing a very interesting project recently. I have to solve everything (even content search) in the browser. The website has no contact to the internet at all...Yes. A website without internet connection or server contact. It will be an information box with touch screen on my former college. It will work as a digital doorman and it's quite nifty (and heavy like a mountain). Our designer did his job very well. It has now a very nice touch compatible interface. (Print screens and actual "in-use" images soon)

The computer runs on Ubuntu and unfortunately nobody knows the root password :) That's why I'm sticked with Firefox. The base hardware is... very environment (therefore not too user-experience) friendly, but I will do my best. Later, when I will have more time I will reinstall the system and use Chrome instead. The Javascript animations are much faster there. And I did a little test with flash. Surprisingly (at least for me) Opera handles Flash animation much more smoothly than any other browser. I designed a little active backgound for the whole system, and it looked awesome in Opera (I tested it with an Ubuntu live CD).

I have came up with a solution, I just want to test it. If it works, I will write a full post about it. If it won't than I will write it down, why it didn't worked.

But now I have a very tight deadline so I stop writing posts and go back to work :)