The council gave each tree in this Melbourne park its own email address, intending to make it easy for the public to report any issues; dangerous branches and the like.
Lo and behold love notes addressed to individual trees started rolling in from locals. Technology had allowed people to demonstrate their love for nature. Some of them even got replies when the council started playing along (see examples in the link below).
This is reminiscent, as the article points out, of the Tweeting potholes of Panama, which would tweet the council every time a car went over them. Soon after, the roads were all smoothed over, as the story goes.
These ideas are very similar and very simple. They are also ones that seem to have had a huge impact on the surrounding people, which is what I love about them.