IEAK 7 makes it easy to deploy your own customized version of IE7. Both Google and Yahoo try to convince IE6 users to upgrade to their version of IE7. Yahoo does that by promoting the bundle on each and every search results page, while Google bought some AdWords for "ie7".
I wonder if there's a strict template companies should follow or Google and Yahoo are completely unimaginative.
Google also "optimizes" Firefox
Update: Jeremy Zawodny, from Yahoo, says there's no template and Google copied Yahoo's page. Google changed the page and Matt Cutts wrote a short post about Yahoo copying Google.
4 hours ago