At least 92% of adults in the UK use a mobile phone and the number for users with smartphones is expected to pass 50% very soon. Finding good uses for information from our phones looks like a smart idea. To avoid the problems of normal weather reporting, OpenSignal from London were inspired by the increasing number of high-tech sensors in our smartphones to measure air pressure, humidity and the Earth’s magnetic field to make mobile phones mobile weather stations. They have started an online service, called WeatherSignal, that takes meteorological information from android smartphones and maps it online, so we can find out what the weather is actually doing right now in our local park.