The “wisdom of the crowd” concept where the averaged opinions of thousands of people is used to evaluate the worth of a product or idea is a certainly big part of today’s web, think of Amazon Reviews, TripAdvisor.com or Digg. As much as it’s a part of the current web 2.0 buzz it’s not a new idea.

Zagat Survey has been applying the “wisdom of the crowd” since 1979. Its first product was a New York City restaurant guidebook based on reviews submitted by thousands of reader volunteers. Zagat has since expanded to cover hotels, night spots, golf courses, entertainment and shopping in over 70 cities around the world.

Nowadays besides paper guidebooks, Zagat has a big web presence and offers mobile guide applications for Palm, Windows Mobile, Symbian and Blackberry devices. This week they launched Zagat.mobi on the mobile web.

The mobile site’s coverage is limited to restaurants, hotels and night spots in 16 US and Canadian cites plus London, Paris and Tokyo. (Update: All 100+ of  Zagat’s US cities are available on the .mobi site.  They aren’t listed in the dropdown but will appear if you enter the city name or zip code in the search box.)   For the covered cites the mobile and web listings seem essentially identical. Like the web site, the .mobi one is free to browse without registration. However the Zagat ratings are only available to paying customers. To see the ratings you must join Zagat for 24.95/year or 4.95/month. Even without ratings Zagat.mobi is useful. The listings give hours of operation, details like type of cuisine and include click to call phone numbers and the ability to send a listing to any phone number or email address. One feature of the mobile site that’s not available on the web is that you can browse Zagat’s top 5 picks for quality or price. You can even sort results by those criteria – which is almost as good as being able to see the ratings. There’s a handy Find Nearby feature for bar hopping or when the wait for a table is too long and you want to find another place in the neighborhood.

The mobile site is well designed with an average page size of 5 KB plus about 9 KB of images. It should load quickly and work well on most phones. Numeric shortcuts speed navigation by providing single click access to features and reviews.

One thing I noticed though is that if you go to zagat.mobi with a desktop browser or a mobile browser that Zagat’s doesn’t recognize you’ll be rediected to the desktop page at www.zagat.com. That defeats the biggest, perhaps the only, advantage of a .mobi address which is that it should always point to a mobile site. Browser detection is great when it works. The trouble is that it doesn’t work 100% of the time. Every site that does browser detection needs to have a direct link to their mobile site on their desktop page and another link on the mobile page that always delivers a desktop page. That gives the user who is redirected to the wrong site a way to recover.

Zagat.mobi: zagat.mobi

Rating: Content: Usability: