Firefox's built-in search box lets you search Google from wherever you are. You don't have to settle for that built-in searching, though, because you can build your own Firefox search engine plug-in to search through any site from the Google search box.Source: O'Reilly Hacks
Not that this really belongs in a Windows XP Hacks book (great book, by the way) but it is in there nonetheless. Making your own search engine plug-in isn't hard at all. I am working on one for bgnews.com.
