Watch Your Privacy
Augmented Reality app for Google Glass by Sander Veenhof will let you know where there are surveillance cameras in public spaces - video embedded below:
Google Glass a privacy problem? It can also be the solution for those worried about with privacy: buy a Google Glass!
Use this handy augmented reality app that visualises nearby privacy intrusions, based on open data about surveillance cameras worldwide (And it accurately maps your fellow Google Glass users too!)
Related - by the same artist - a screensaver for Google Glass when nothing of interest is around: