I had conversation with @mattwilliams about weather and how it would be great to have some tools that will tell you if it will be warmer / colder than yesterday. So you can decide what to wear or what to bring (like umbrella) with you to work. So I build it and you can try it here. Let me know what do you think.
From developer point of view:
Whole thing is build in latest rails. I’m using Google API (that have no documentation) for weather feed, Twitter for messaging and for authentication. The whole thing is hosted on Heroku.