In late March, Google was awarded a slightly unusual patent — for advertising based on environmental conditions. That sounds odd enough, but how it will work is even stranger. The idea is to have in-built sensors in mobile phones that can gather information about the user’s surroundings; based on that, relevant, targeted ads will pop up on screen when the user browses the net. For instance, on a blistering hot day, ads for ice cream or air conditioners could appear.