Its said there are three things we all love to watch- Fire, Water and other people working! As fire is generally too dangerous in public and we cant just pay people to do their work on the streets that leaves water as a universal focal point. Being Irish there is alway lots of water around, generally falling from the sky and I would love to see this taken advantage of in design. That said here is some inspiration I have been collecting.
Sources are under the image titles. For more inspiration feel free to visit my denizine of online hoarding- pinterest!