According to this MIT Technology Review article, researchers at the University of Washington have developed prototype devices that communicate using just ambient radio waves — no batteries needed. The devices achieve this trick by varying how much they reflect and absorb radio waves, and scavenge power from those same radio waves. Bandwidth is low — only about 1 kilobit per second — and range is currently less than 1 meter, though that can reportedly be extended to about 6 meters easily. By eliminating batteries, such devices can become significantly smaller and cheaper, and could appear in a wide variety of scenarios, from contactless payments to warehouse item tracking, plus the killer app of locating your glasses and keys. follow link
Type an em-dash on an iPhone
Typography and punctuation geeks rejoice! It's easy to type an em-dash on the iPhone's or iPod touch's virtual keyboard. To do so, tap the .?123 key to switch to the numeric keypad. Then touch and hold on the Hyphen key to reveal a pop-up strip showing an em-dash. Slide to the em-dash and release your finger.
Note that this basic trick works with many other keys on the virtual keyboard.
- ExtraBITS for 19 August 2013 (19 Aug 13)
Researchers Demo Devices Powered by TV Signals