Although Google does a fast job of searching, there are a number of things about it as a search tool in the forum that I don't care for. Since these are the days for voicing suggestions for improvements to this system, I thought I would mention a few, and see if anyone else has ideas.
Once you get search results, you are on a Google page, and no longer in arduino.cc.
This means the user has a context switch to make, since all of the forum UI conventions are gone. In fact, you have to use the BACK button in your browser to return to the forum. This is annoying although not catastrophic.
It might be better if the search results were generated in a new tab or window instead of replacing the current one.
Printer-friendly pages are included in the search results
These are not really useful in search results, as they just duplicate other search hits from the keywords. I assume that whenever someone formats a page for printing, that it is retained and then indexed? Could they be excluded?
You lose all forum hierarchy in search results.
It is useful when sifting through search results, to know in which forum category and sub-category the hit is located. You can probably figure it out by looking at the actual URL of the result, but this is cumbersome.
And really, you'd want to be able to sort the results by forum category so you could discard whole groups of results if a too-general search keyword got hits in many categories. Many forum search tools allow you to restrict the results to specific categories and sub-fora.
Although making fixes to some of these things might improve the searching, in my opinion the entire forum would be a smoother user experience with phpBB instead of YaBB, for example.