That’s how one of the Spout folks described the “Create a Document” feature you can add on to your Gmail, whether traditional or through Google Apps for Small Businees, account. It adds a button on the right side of the page that lets you turn that email thread into a Google Doc instantly. So if you have a conversation that’s been going on that you want to archive for later use this let’s you easily and effectively do so.
To turn that on for your account just visit your Settings and then click the Labs tab and scroll down to find it.
You can read Read/Write Web’s write-up of that feature here.