The idea of wireless electricity used to sound absolutely ridiculous to everyone but Nikola Tesla. How could one wirelessly transfer power over the air without either killing someone or giving them some sort of cancer? But some new technologies are making this a seemingly safe and practical reality…at least on a small scale.

Popular Science has a good write-up in their Coming Soon section of the magazine this month (sorry no links as of yet are up) detailing techniques such as charging small devices like cellphones by sending power over radio waves. The transmitter could be hidden somewhere around the house (they use a lamp as an example) and also long as the cell phone was within 10 or so feet and attached to a power receiver (something about the size of a coin that could eventually be built-in to devices), the cellphone could recharge wirelessly – no cable between the power source and cellphone!

Another example which could be even more interesting calls for charging by induction. You place a device like an MP3 player in a special cradle (that isn’t hooked up to any power source) and the coils in the cradle could charge the device. PopSci talks of embedded these coils under a counter top and then anything you place on that surface could be charge simply by sitting on it, very cool stuff.

Also included is talk about wireless HDMI, something which I am very interested in recently as I’m looking to purchase an HDTV. I’ve always hated having to pull out my current TV to plug things into the back via composite, component, S-video, or coaxial cable…but wireless HDMI would eliminate all of that…and in full high definition no less.

It would basically work the same way the a wireless router does, sending a lot of data over the airwaves but at a larger scale (something like 3 gigabits per second). The companies Philips and Tzero have supposedly come up with a way to send uncompressed hi-def video (1080p) and audio up to 25 feet wirelessly. Other companies are working on similar devices to send signals up to 100 feet wirelessly. That would be very, very useful.

[UPDATE]: Wireless charging is all of a sudden blowing up on the Internet since CNN Money ran a story on it.