Best approach(es) to implementing site navigation

[eluser]Fred Riley[/eluser]
Thanks for the reply. I have set up header and footer views, and the top level menu appears in the header. However, my design is that the second and third-level menus will appear in the page body text - see this page which has all 3 navs visible

So the clunky approach would be to have a view for each of the top level sections, with a different subnav in each, but that would lead to update problems as the site grows. Hence my thinking that the menu items for all navs should be defined just once, perhaps as an array constant. If I went that way, where is it best to put global constants? In /libraries, perhaps, or /config?

Cheers

Fred