One big complaint about search engines is they are all rather vanilla with their visual representation. Wouldn’t it be better if you could color code things a ‘bit more? One Greasemonkey script that does a great job at this is Colorful Search.
Once you install this user script, it will generate a random light background color for Bing, Yahoo and Google. Colors are decided and grouped together based on the domain name they come from. So you can quickly see that if Firefox Facts results are light blue, and you see 7 out of the 10 results are light blue, they all came from here. It makes the visual representation much more useable.
Want to color code your own search engine results? You can pick up Colorful Search from userscripts.org.