Mahalo launched yesterday to much fanfare. The reference tool comes from Jason Calacanis, the entrepreneur behind Weblogs, Inc. and the founder of the Silicon Alley Reporter. Billed as “the world’s first human-powered search engine”, Mahalo is a cross between Wikipedia and the Open Directory Project. All three use human editors to deliver, theoretically, better answers.

The goal of Mahalo is to curate the “head” of search queries – the queries that are the most popular. Mahalo currently covers about 4,000 terms, with the goal of expanding to about 10,000.

Searching for popular terms like “Britney Spears”, “iraq war” or “Wii”, returns results that have been written by a human editor. (Searches for terms that Mahalo doesn’t cover return Google results.) Part of the premise is that a team of trained editors won’t be gamed by SEOs and SEMs the way an algorithm can be.

Unlike Wikipedia, which is open for anyone to edit, and the ODP, which has about 8,000 volunteer editors, Mahalo has a small team of staff editors. Where Wikipedia focuses on facts and ODP on Web sites, Mahalo offers a mix of the two and then some.

The content of the search results pages vary dramatically based on the content of the term. The search for Wii brings up categories such as News, Reviews, Retailers and Coupons and Deals. A search for Steve Jobs brings up videos, photos, a profile and a bio. For someone looking for basic information on a topic, Mahalo provides quick nuggets of information. A section labeled “The Mahalo Top 7” is consistent from page to page.

Mahalo mixes in feeds of information on fast changing subjects. In the search for “iraq war”, you get headlines on the topic including a story from Reuters and a feed from Fox News.

One of the challenges of human-edited results is that even in a limited universe of 10,000 pages, things change and pages get outdated quickly. Links can break. News becomes old. The Iraq War page’s News section has the headline “House OKs Iraq bill with timetable for pullout”. The story is more than a month old and has been superseded by more recent events.

The other big challenge is that it brings up the question of bias. Does the choice of Fox News as the feed provider for “Hillary Clinton” reflect a bias on the part of Nicole Gustas, the editor of that page? Or is Fox News the only feed easily available?

Results can be quirky, reflecting the whims of editors, both in terms of what’s covered and what’s on the Mahalo page. Searching for “Larry Page” or “Sergey Brin” didn’t bring up a Mahalo page, but you do get Mahalo pages for “Kevin Rose” and “John Battelle”. The #4 link on a search for eBay is a link to the member profile for andy46477. I’m not sure if that link, designated as a “Guide’s Choice”, is an inside joke that I’m missing.

The site has a playful feel to it, from the name (which means “Thank you” in Hawaiian) to the shaka (sorry, no Mahalo results for shaka), next to Guide’s Choice links.

Mahalo is backed by top-flight investors including Sequoia, Elon Musk (co-founder of PayPal) and News Corp.

On the whole, it’s an interesting experiment. I don’t see Google shaking in its boots over Mahalo yet, but I can see using it when I’m looking for a quick overview on a topic. And with the serious backing, it’s definitely one to watch.