One of the big problems with Weathrman’s current implementation is that the whole implementation lives in your phone; a worst-case search can trawl through literally tens of thousands of search results, searching for an image relevant to your weather conditions and time of day.
Many of those searches are common to others; city-level searches are the same all over London, for example; local searches are the same for everyone sitting near me. Much of this can be cached aggressively, massively reducing the amount of time it takes to get good results, and allowing me to do more searches, more often, at less cost and lower latency to end users.
It’s not ready yet - I’m nearly ready, probably another day away or so, and I’ll probably test it out for a week or so. Come Google I/O, though, I’ll be ready to ship.
It’s notably faster, and pushing the image scaling to the server has resulted in massive improvements in image quality, while turning hundreds of RPC calls to flickr into a single call to the weatherman service.