In the relentless game of public search engine leapfrog, Yahoo! may have just leapt into the lead. It has added some fresh intelligence to help the hesitant user.

No doubt other search companies will already be unpicking the Yahoo! offering to see whether they can improve on it. And it's highly likely they can. But, for the moment, Yahoo! is the benchmark with its 'Explore concepts' extension.

Yahoo! senses when a user hesitates while typing a search query and pops up auto-complete suggestions. This, of course, is not a new idea. The new bit comes when you get to the results page. If the results aren't what you expected, you can click on a little arrow to drop down a panel containing the autocomplete suggestions and an 'Explore concepts' section to the right:

In the above example 'information world' produced, not surprisingly, over a billion results. The autocomplete would have done the job for you and me, but the concepts on the right are designed to help the user who's thrashing around a bit.

As you click on each concept, new search results appear along with the concepts which relate to the new search expression.

I tried 'electron spin resonance', about which I know little. After clicking through 'free radicals' (thought I might hit a political pressure group), I was intrigued by 'magnetic moments'. Here's the first result.

Bear in mind that this functionality is not part of some hugely expensive enterprise search system, it's freely available to the general public.

If you're like me, you've regarded Yahoo! largely as an organisations that wants to push ads at you and keep you within its semi-walled garden. A bit of a turn off, especially in Europe apparently. But developments like this and, in a totally different context, Pipes suggest that Yahoo! has realised that life is not all about take, it's about give as well.