A Search Box Within Google’s Search Engine Results Page?

Searching this afternoon led me to an interesting discovery: a search box, located right in the Google Search Results Page:

site search google serp

I can definitely see the power of having a function like this – especially for large, robust websites.

Performing a search for “maine” in this search box would surely return a search result page from the US SBA website, right? Wrong.

site search results

A Google search result page of the website is served up.

Having neither seen nor heard anything about this, I started looking around for an article about it. No such luck.

Has anyone else seen anything like this?

Update: Shines and Jecker was kind enough to point me in the right direction.

Nicki Hicks
(Un)stumped
.