I'm not so vain to think myself more clever than the hundreds of PhD's that work at google, so in addition to the regular site search, I've added Google's AdSense for Search to the site as well.
Unfortunatly, Google's Terms & Conditions, as well as their technology, prevent me from specifying a particular directory to search under, so this is going to be searching all of gliff.org. If a page title doesn't include the phrase United States Geological Survey Digital Data Series, then it's probably not relevent to the USGS site.