Maybe you already know about OmniWeb's shortcut feature, by which you can type something like google RPS in the location field to go straight to the Google search results for RPS. You can set up more shortcuts by putting your cursor in a search field at any site and clicking the little magnifying glass that appears at the bottom of the window.
One such keyword that comes with OmniWeb is *; it appends www. and .com to what you type. So if you type worldrps it takes you to www.worldrps.com. That's handy, but I wanted it to do something even smarter. I changed that shortcut's URL to this:
Now when I enter anything that's not a URL, I end up at Google's best match for what I typed. This is super-handy when I know the site I want to visit, but I can't remember the URL. Like, who can remember that the Subversion manual is at svnbook.red-bean.com? Well, now I just type subversion book in the location field and bam, I'm there.
Of course, this shortcut works best when you know there is a single definitive site about the thing you're looking for. Give it a try today.