Julian Oliver created the Transparency Grenade in January 2012 for the Studio Weise7 exhibition at Labor 8. It's a transparent device with a "payload" built from an ARM Chip, an Arduino Nano, a mic, and a strong Wi-Fi antenna. It taps into wireless networks and logs emails, webpages, images, and voice to a publicly available online map showing its "detonation" location. Apparently, development for an Android version (sans the pretty plastic shell) is under way thanks to interested donors. See their website for more details.