How do you find a new search engine if all you know is Google? Typing "search engine" into the usual box might lead you to Microsoft's newly launched Bing, the combined search at Dogpile, or the former king of search, Altavista.

But for those willing to dig around, searching for search engines can reveal a treasure trove: The net is rich with specialized search services, all trying to find a way to get their slice of the billions of dollars Google makes every year answering queries.

For this article, we surveyed some 50 specialty search services and picked out our favorites. What follows is not a systematic ranking or review, but a general guide to a very vibrant world that few have bothered to explore in depth.

The variety of search startups is mind-boggling, and hints at the challenges Google may face staying on the bleeding edge of search innovation in the coming years. (There's even something for micro-philanthropists: Good Search donates a penny to the charity of your choice for each search you run.)

None of the sites we sampled are likely to replace Google as your go-to search engine for general queries, or dent Google's growing sway as the world's information broker any time soon. But even a cursory tour will make you start to think differently about what's possible in search, and show up some of Google's shortcomings.

Take mobile. Google works fine on the iPhone, but for quick searches on the go, ChaCha can't be beat. Simply text your question to 242242 and you'll get an answer sent back to you.

In the age of Twitter, there's fierce competition to be the quickest indexer on the net – a feature even Google co-founder Sergey Brin admits his company can improve upon. IceRocket, OneRiot and Scoopler are typical of the trend.

The smartest one we found is Collecta. It scours the net for the most recent blog posts, news stories, tweets and comments and displays them in a continuous waterfall. It's a torrent of information to keep track of, but if you are worried about your company's online reputation or want the latest news on Iran, it's indispensable.

Keeping tabs on local news and events isn't easy – even in the days of news aggregators. Enter Trackle. Think of it as a standing search engine that will notify you of news and events you want to know about. Want to follow stocks, know the weather, find news about your neighborhood, buy a treadmill on Craigslist, follow the big game while at work or find deals on specific products? Trackle searches constantly for you and sends you emails or text messages (your choice) when Apple stock falls or your team scores a run. The interface is clunky, but the idea of a search robot beats the hell out of an RSS feed any day.

Want to learn about a general topic such as the Iranian revolution or paella? Try Kosmix.com, which relies on services around the web – like Wikipedia and Flickr – to compile web pages stocked with useful and relevant information.

Some of the most interesting search engines we found are those that focus on a narrow niche and deliver in-depth targeted results on very narrow topics. Familiar examples are travel sites like Orbitz and Kayak, which search multiple databases to find cheap airfares and hotel rooms.

Newcomer Voyij is a travel sale search engine that looks exclusively for deals departing from your home city. The site's focus is more on people ready for an adventure than on business travelers looking for a cheap ticket. The top return on a recent search for Chicago vacation packages was $193 per person for a two-night trip to Bloomington, Minnesota, staying at the the Ramada at the Mall for America. If a mall with a waterpark isn't your thing, you can shell out about $25 a piece more for a trip to Minneapolis where you'll stay at the Millennium Hotel. (Yelp to see if it's any good).

Don't even have the scratch for trips at those prices? Try Indeed.com, a meta-search engine for job hunters. When you get to the interview, fire up Parkingspots.com to find the best place to put your car.

Want to see a concert to celebrate your new job? Pick up a ticket using meta-search eningesFanSnap.com or ZebraTickets.com.

Some search innovators are tackling interface design to help take some of the guesswork out of search links. If you're looking for something visual – say Michael Jackson moon walking – try Searchme.com, which shows entire web pages in its results as if they were album art in iTunes.

For music, try Fizy.com or head to video search engine Blinkx.com to navigate your way to streaming songs you can't find anywhere else.

When it comes to modern web searching algorithms rule the roost, and attempts to improve results with an assist from the people who use them have generally failed. Google's search wiki feature has not gained much traction and Wikipedia founder Jimmy Wales's human-powered search engine went out of business.

But that's not stopped a handful of companies from trying to one-up Google by inserting a human element into search.

Scour, a customizable meta search that let you choose which of the Big Three's (Google, Microsoft and Yahoo) search results should be favored, and lets you mark sites as spam and add comments. Xmarks.com takes its popular bookmark synchronization browser plug-in and uses that data to overlay information on search results from the big search engines.

Hunch, the much-hyped site started by Flickr co-founder Caterina Fake, doesn't want to be a search engine at all. Like Microsoft's Bing, Hunch is supposed to be a "decision engine" that cuts through the deluge of web data to give answers. You tell it a bit about yourself (such as a favorite historical figure) and it will try to help you decide whether to get a 50lb mutt or a pedigree, designer Puggle. It's entertaining, but so far its suggestions aren't impressive.

Supernaturalrecipes.com and foodblogsearch.com are cooking search engines that cut through unfiltered recipe search results with handpicked sites delivered through a custom Google search engine. Both have good result if you are looking for a good gnocchi recipe or if you need a recipe to take care of all that basil and couscous in your house.

Then there are search engines that mean business.

Take Spyfu.com, for example. This little secret agent focuses on Google's AdWords program and will tell you what keywords your competitors bid on, how much they pay per click and what the search volume is for various search terms. It feels illegal and is totally fascinating. Check out how much GM used to spend on little text ads before its recent crash. For serious advertisers, there's a premium version too.

Panjiva tracks overseas factories and their U.S. customers by indexing publicly available customs data. It's a great way to keep track of where your competition is getting their products made and by whom. But more importantly, it's an amazing demo of what can be done with open government data, and one should expect to see more examples like it, now that the feds have committed to sharing raw data with the nation via Data.gov.

Then, of course, there is Wolfram|Alpha, the net's algorithimic genius that the tech press is agog over. It can tell you the relative humidity of the city you were born in on the day you were born, and it does calculus, too. But it's not a search engine.

Got your own favorite that we missed? Drop us a note in the comments.

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Update: This story was updated to include Wolfram|Alpha, which was left out due to an editing error.*

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