True Knowledge, which is currently in private beta test mode is an interesting new search engine. It allows you to simply ask questions, but has the addition of being Wikipedia/Wikia Search/knol like in that you can add or amend the information that you find. They've got a blog that is actually interesting and informative as well, in case you want to explore a little further, and there is also a wiki. A final piece of trivia before I actually start to talk about the engine is that it's based in Cambridge in the UK.
Some of the questions that you can ask are:
What was the age of Queen Victoria on 2nd June 1859?
Who was the Prime Minister of the UK in 1978?
How far is New York city from London in miles?
Who was born on January 1st 1960?
List curry houses in Cambridge
You can also view profiles of individuals, though these only tend to give basic factual information.
You can add in information yourself; a person, place, business or something else. This element of the engine is perhaps the most interesting, in comparison to other similar resources in that you really have to go through a lot of hoops to add content. This is both a strength and a weakness, since you have to define classes and objects and so on - I tried it and found it was quite dizzying. However, if you find some information it's easy to amend it - I did a search on Everton (football club) and the first thing I had to do was clarify exactly what Everton I was interested in. I then got some factual content about the club, but the name of their ground wasn't included so I was able to add that.
Search results are interesting, because this search engine tells you exactly what it thinks you have asked. I asked the question 'How old is Gordon Brown?' and got the answer "the age 57 years, 7 months and 2 days old". The Google answer was rather less helpful; Age: 57 years (born 20 February 1951). Live.com didn't give me an answer at all, Yahoo pointed me to the Wikipedia and didn't give me an answer, while Ask told me he was 57, but didn't provide any more detailed information.
Under the answer at True Knowledge was the explanation "(I understood your question to mean: Which age is the age (length of time since creation) of Gordon Brown, the British politician at the current time?)" Now that's a bit ponderous, but it certainly works!
The interface is ok - it's not the best that I've seen, and below the answer True Knowledge gives are a bunch of answers taken from I'm not sure where, but I didn't find them impressive at all - I'd be inclined to ignore those to be honest. There isn't an advanced search function because the engine doesn't work like this - it's very semantic in approach - just type in a question and see how it gets on with it. It's currently answering queries based on 107,431,249 facts about 4,130,828 things. It knows about (for example) 2,392,956 settlements, 374,957 human beings, 38,091 movies, 19,251 bands, 4,456 battles, 1,223 horses, 108 countries, 51 UK police areas, 11 Belgian Provinces and so on.
Of course, there are plenty of reservations about the engine - the bias and reasoning behind adding to the engine - I saw a few examples of individuals adding content about themselves, which is fine as far as it goes, but that can easily spread from facts to embellishments, all the problems that Wikipedia has keeping a clean and accurate database - all the things you'd expect. It can deal with factual questions reasonably well, but it gets confused if you ask for subjective content, which is fair enough.
Now, as I mentioned at the start of the post, it's in private beta, but I have 20 invitations to give out to interested people. Please reply in the comments field with your email address (don't worry, I won't publish these as comments and will delete them once I have sent out the invite) and I'll get an invite winging its way to you.