I’m sure this has been said before, but I’m going to remind everyone:

You should try browsing the web with Javascript turned off and observe how broken many things are.  If you run your own site, see how it responds.

At the least, if your site can’t function without Javascript, put in a check to see if a visitor has Javascript disabled, and if so, give a warning that functionality is not guaranteed.

I’m running with NoScript installed in Firefox.  It’s pretty eye opening.

Take, for example, TokBox.  If you visit there with NoScript turned on, you’ll be greeted by a blank page.  While NoScript blocks more than just Javascript, it’s still embarrassing that with scripts turned off, an entire site results in a blank page.

Don’t let this happen to your site.  Degrade gracefully.