Include a menu on every page? use url helper in a class?

[eluser]haloace[/eluser]
[quote author="jedd" date="1256921226"][quote author="haloace" date="1256893585"]

Code:

include("menu.inc");

[/quote]

I'd suggest this is actually a very old technique.

And I'd strongly recommend you don't do this. At the very least turn it into a helper.
[/quote]

What is the disadvantage of this technique?