Google Chrome: Many of you have been noticing that Google's search results have been less useful lately, and Google's listening: with their new Personal Blocklist extension, you can block sites from your search results and send the information back to Google.
Personal Blocklist adds an extra link to each search result, from which you can block that domain from future searches. Chrome will send that information to Google to help them refine their engine and make their results more useful. You can show blocked search results at any time, highlighted in red, and view your list of blocked domains from the extension's button in the navigation bar. It's just one way Google's planning to make their search results more useful, but it's a good start.
Personal Blocklist is a free download for Google Chrome. If you aren't running Chrome, you can also use site-specific search engines to filter out spammy search results. Your feedback won't go back to Google, but at least you can keep your results a bit cleaner.