That's a nice search tool. I found that the relevance is not quite as good as Google (for example "howdoi get referrer url php") but this could be used when you enter a query that contains symbols.
They also have odata endpoints so you should be able to get at the data (updated weekly) that way. It looks like there is a problem with it at the moment, though (I get 'server error'):
http://data.stackexchange.com/stackoverflow/atom
No way to currently contribute answers. Another commenter mentioned cheat.errtheblog.com that uses a wiki system. The downside is that when the wiki fails (like right now) the application breaks.
You may want to just submit a good answer to StackOverflow and make sure it is well written and gets lots of votes.
Thanks for playing with it. Sometimes the first answer isn't the greatest but -p2 or -p3 will get it. In this case the following command gets you closer: