Instructables user talk2bruce has created a truly great tutorial. In it, he shows you how to build a highly visible internet monitor. The Raspberry Pi is used to ping a site on the internet and then, based on the response, switches the lights in a light tower from red to amber to green. The Instructable is very long, very comprehensive and covers both the hardware build (including a laser-cut wooden case) and the software, virtually line-by-line. Read the Instructable here.