cities full of invisible cues

I like this ubiquitous computing concept in which there are numerous informative cues like virtual post-its, things with url only accessible via mobile devices. That reminds me a kind of strange wizardry ! Or something like the invisibles. A world is hiddent and only some folks could access it. That's why I look into Role Playing Games like Shadowrun to find relevant ideas ! This mix of cyberpunk and magic stuff is smart I think !