Rod has a good tip on searching sites:
Say to look for some words found only in uk sites you can enter in the Google query ...
search term site:uk
The site switch restricts the search to uk domains. To look on my site for a previous posting I entered into Google ...
evaluation site:www.drury.net.nz
Which allowed me to search over just my site.
One problem with this approach is that you come to the older, cached versions of pages rather than the real version on the site... if you get my drift. Is very useful though.