First, there was the labs.google.com test with "search using your keyboard only" (I can't find that link no more.. looks like its shelved). I thought to myself, "Cute, no WEB developer seems to be interested in doing keyboard shortcuts"
Then, Gmail raised the bar for both WebUI and Web-based Email.. not only the much gossiped 1GB space and content sensitive text-ad by the side... but also the wonderful keyboard shortcuts.. and their wonderful show-and-hide style that reduces the (now) unnecessary network round-trip...
Now, checkout Google Suggest and public discussion of how it was done.
I wonder if there's soon to be a defacto enhanced-web-ui project to better the experience of using future web applications. Then again, the future of such a project might be short-lived: The waiting-to-be-incorporated-into-browsers-or-html features may run obsolete by the time its fully done.. Then again, it may not.