Is is possible to create navigational menus for a web page in
PhotoShop/ImageReady that has submenus?

I have used navigational menus created in javascript. I really like
them; they are fast and easy to make.
 
However someone else would like me to see if it's possible to do the
same thing in PhotoShop/ImageReady. I would have to learn how to do
this. The main reason for using Photoshop/ImageReady would be more
choices for fonts.
 
Is it even possible or worth the time to do this in PhotoShop?

thanks

Photoshop only creates images... I'm not experienced with ImageReady,
but I believe it would need some kind of scripting to have sub menus
that pop out when you click them. You can make static images with sub
menus with photoshop, though.

As Mycro said, Photoshop and ImageReady only create images. You still
need JavaScript to create and animate your menus.

What you can do with Photoshop/ImageReady is to put images instead of
simple text in the menu. So you just create the menu entries (labels)
in Photoshop, save them as JPEG or GIFs (you can even make them
animated GIFs with ImageReady but I guess that would be unnecessary
for a menu) and place those instead of simple text in your popup menu.
The rest of your script can remain exactly the same.

Open Adobe Imageready, select (F)ile, (O)pen, and open the example
file called Accelerator.psd

From the main menu, select (S)lices, Preview Rollovers.

That form of animation is exactly what Imageready is capable of
developing for you.

Next, Select (F)ile, (S)ave optimized as... and save it as the
default'ed entry of "accelerator.html".   Now navigate to the folder
you saved the [.html] file to and double click on it.  Notice that the
menu options highlight when your mouse moves over them.  Viewing the
source will show pages of javascript to perform the actions you are
looking for.