Google Dominoes is an extension for either the Firefox web browser that provides you with a special kind of Google toolbar.
From Google's home page, you can use Google to search the web or to navigate directly to the first item on a list of search results by pressing the I'm Feeling Lucky button. With Google, pressing this button sends you to the page that Google thinks will be most Lucky for you; however, Google Dominoes lets you decide which page is most Lucky for you.
For example, suppose you live in Cambridge, MA. Thus, when you search for weather in Google, it would be really nice if the site that had the National Weather Service's forecast for Cambridge would show up at the top of your search results page. Using Google Dominoes, go to the NWS site for Cambridge, type weather into the Google Dominoes text box, and then hit the Make This Lucky button. Now whenever you do a Google Dominoes search for weather, the NWS site will appear first in your list of search results. What's more is that if you type weather and hit Feeling Lucky?, then Google Dominoes will take you directly to the page! Instead of wasting time bookmarking pages and filing them in some bloated tree of bookmarks, just Make Them Lucky instead.