StumbleUpon‘s Firefox add-on now provides enhancements to Google search. StumbleUpon leverages its data on what thousands of users like and don’t like on the web to add human ratings to Google search. StumbleUpon adds a 5-star rating, category tag, and a comments link next to search results, giving you a better idea of which are the good links.

For example, I searched for “iphone apps” on Google, and StubleUpon immediately drew my attention to what turned out to be two of the better links on the page, appleiphoneapps.com and Lifehacker’s 20 Best iPhone apps post.

What would really be nice, once StumbleUpon has enough data, is for them to build their own search engine and integrate it into their browser plugin. Despite many saying search innovation is dead, it can still be challenging to find what I want on Google.

Yes, Google’s algorithm is amazing, but there’s a human element that search is lacking. Despite progress in AI, people can still determine what’s relevant or not better than computers. StumbleUpon, with its growing wealth of data on what people like on the web, is well-positioned to enhance search with a touch of human input.