Earlier this year, Google hosted an event called "Searchology," at which the company announced its search options. These options come in the form of a link on Google’s search results pages, which simply says, "show options."
Within these options, is an option called "Wonder Wheel." It’s been around a while, so there is a good chance you’ve heard of it, so if so, great. If not, it’s a way to search for related searches in a graphical way. It looks like this:
You can click around on it and bring up new wheels based on the related search you clicked on. So if you clicked on "nike shoes" in the above example, you would get other searches related to "nike shoes".
You can keep going with this as long as you wish, and it is one way for a searcher to expand their quest for finding the information they’re looking for. However, if you search well enough to begin with, chances are, you won’t have a whole lot of use for this.
Google’s Matt Cutts makes a great point about the Wonder Wheel in the following video though. If you use it as more of a keyword-generating tool, you may find it useful indeed.
If you are running a business and are looking for keyphrases that may drive traffic to your site, or need some ideas for keywords to bid on for search ads, you can find some relevant ones this way.