This is all good and well, but "how do I configure it?" I hear you ask, well here's how:
1. Navigate to Site Actions > Site settings
2. Click on the "Search keywords" link (found under the Site Collection Administration section.
3. You will now be presented with the following screen.
4. Press the Add Keyword button as circled (with much artistic skill may I add) above.
5. Now fill in the form provided (see the image below)