I'm not familiar with Google Analytics but I think you can use it to see how many people get to your site using different search strings.

But if you don't yet have the site, can you simply ask Google how popular a search is? For instance say you're choosing a new product name/slogan/etc. First of all, you want to see if that is already very crowded, which is easy through just Googling it. But now you might want to see if anyone is actually searching for this... an ideal situation would be to find a search-string lots of people are using, which doesn't put your competitors on the #1 spot.

Is this possible? Not exactly programming-related, but closely related to web-development IMO... please vote to close if you disagree, I won't be offended!