If you use a Mac but haven't heard of Quicksilver yet, you're wasting clicks and keystrokes. It is the equivalent of ActiveWords in the Windows world, but with a host of community-contributed plugins and a deep framework for customization.
In fact, I used this framework to remedy something that was bothering me once I became better acquainted with Quicksilver: lack of browser-independent web searches. If you have been frustrated by not being able to use a browser other than Safari, OmniWeb, or Internet Explorer to display the results of Quicksilver Google searches, check out the AppleScript at the end of this article.
Quicksilver recommends creating a special bookmark to use as your method of displaying web searches. While Firefox users can download an additional plugin to catalog their Firefox bookmarks, using browser bookmarks to launch searches is still just a bit clunky, requiring three columns in Quicksilver to perform a search.
I decided it would be more elegant to let the user specify which browser to use at the operating system level, and found that in doing so I could simplify the process so that I only type four additional keystrokes (besides the invocation of Quicksilver and the search term itself) to get my search results displayed in the browser of my choice.
The resulting AppleScript should be placed in ~/Library/Application Support/Quicksilver/Actions/ . If the "Actions" folder does not exist, create it. Then refresh the catalog using command-; then command-r (then command-w to close the preferences window).
From here, the sequence to get a Google search done is period (to enter static text mode), then the text to search, then tab, then 'g', then enter. Quick, painless Googling thanks to the flexible architecture of Quicksilver.