Exactly. I use it even for sites that have search - it's much more accurate.

And if you search a site often, you can create a macroexpansion for the address bar - e.g. in my browser (safari + sogudi) "w lisp" expands to http://www.google.com/search?q=site:en.wikipedia.org+lisp

Don't ask others to solve your problems, solve it yourself.