Mark Pilgrim has released an amazing browser enhancer called "Butler" (requires Firefox and Greasemonkey) that adds loads of functionality to Google:
* removes ads on most Google pages * fixes fonts on most Google pages * Google web search: o adds links to other search sites ("Try your search on...") o in news results, adds links to other news sites o in movie results, adds links to other movie sites o in weather results, adds links to other weather sites o in product results, adds links to other product sites * Google image search: o adds links to other image/photo/art sites * Google News: o adds links to other news sites * Froogle: o adds links to other product sites * Google Print: o Removes image copying restrictions o adds links to other book sites * Google Toolbar Firefox page: o adds links to other Firefox-friendly toolbars
(Thanks, Dan!)