Google relauched SiteMaps as WebMasterCentral. As they increase the statistics provided, this will become a useful resource. More transparency into the crawl and the index are always appreciated.
One great steal-this-usability-idea for retailers is the flyweight "rate this tool" survey. Just three little icons (happy smiley, indifferent smiley, sad smiley) tied to a smidgen of ajax to send the response and remove the icons after a click. Many web surveys are too long and ponderous; this super light-weight "what do you think of this page?" is really powerful.
(Back when I headed marketing at Crutchfield, we tried a similar "rate this page" with a binary "thumbs up / thumbs down" feedback which provided highly useful user feedback. We got the don't-ask-for-too-much-info part right, but could have done much better on the interface had we kept the survey on the same page and used thumb icons.)