alternate text navigation

[Cary19]

Hi,
When I took an html class a long time ago, I was taught to always provide alternate navigation at the bottom of the page using just text and a link, if my only navigation at the top of the page used an image or other things that might make navigation unaccessible. I've noticed that most sites don't seem to have this anymore. Does it have something to do with CSS being used, or what? For example, I went to the famous web designer's site (Jeffrey Zeldman) at www.happycog.com and I'm not sure (I'm not very experienced) but it looks like his navigation at the top of the page uses javascript rollovers. Maybe not. And he's really big on accessibility, but there isn't any alternate navigation that I can find. As they say, what's up with that?
Thanks for any help.
Cary

[Zach Elfers]

He might have a browser detection script which determines if the browser is capable of certain things. Then he sends it to the page that is best for that browser.

[jeffmott]

Cary19
I was taught to always provide alternate navigation at the bottom of the page using just text and a link, if my only navigation at the top of the page used an image or other things that might make navigation unaccessible

You're supposed to provide alternate text for images. This will allow the navigation to be rendered as text if the user cannot view images.

Cary19
looks like his navigation at the top of the page uses javascript rollovers. Maybe not. And he's really big on accessibility

A JavaScript rollover doesn't affect accessibility. Anyone without JavaScript or who is not sighted will not be able to see it, but won't prevent them from using the navigation.