As you know, Safari includes integrated Google
search right in the toolbar. Just
type in your search, press return and you are taken directly to the Google results.
Coupled with SnapBack (that orange icon that appears after clicking a search
result page), this is a very convenient way to browse and search the web.
On the Google front, Safari supports a contextual menu with
"Google Search" to search based on text that you find on a page itself. Just
select the text you want to search on and ctrl-click (or press the right mouse
button on multi-button mice) the selection. Choose "Google Search" and you
you are taken directly to the results page.