invention of the radio?
967817
These links should do it for you.  Good luck with your project.
219200
Since the 21st Century started in 2000, the computer and internet would not be a vaild response. I believe the greatest invention is the i-Pod. :)
632045
No one invented electricity. It was discovered.\n\ntosmith
233686
I found this link. Maybe you can check it out as they talk about starting a powerful FM radio station and a low cost alternative. http://www.prometheusradio.org/alt_startfm.shtml
417242
Something he invented.
241096
Radio is controlled by The Man.
407781
The answering machine, the UNIVAC 1 (first commercial computer), super glue, the videotape recorder, MR. POTATO HEAD, radial tires, the 3-D movie, oral contraceptives, velcro, the hoola hoop, and the snowmobile.  Take a look at\n\nhttp://www.fiftiesweb.com/pop/inventions.htm
285944
This is sort of like the chicken and/or the egg. But The principle (undoubtedly) was discovered, but the implementation of the object was invented - ie it is the combination of axle, hub, and bearing that is the invention, allowing a wheel to be attached to a cart or similar, to make it useful.\n\n The idea of perpetual motion is nothing new. It was discovered and proven in the beginning of the 18 century. The invention was a working system using the gravity force to power the wheel. This made the inventor famous in history. \n\nThus, in summation, I firmly believe that the wheel was discovered just by observing nature but the axle, etc was invented.
675236
Indoor plumbing, the transistor (without which there would be no digital electronics), plastics.  I would agree with the "wheel" answer, except that it came around long before the engineering profession and was probably invented by some caveman.  You could also include scientific principles that have been discovered and subsequently led to great engineering feats.  For instance, Maxwell's Laws of Electromagnetism (the principle on which all wireless devices work), Bernoulli's Principle (the basis for airplane wing design) and so on.
362672
Radiowaves, look it up.\nAnd you definately got the category wrong.
216733
Here's a link that'll help you best\nhttp://radio.about.com/library/weekly/aa013003c.htm
656326
Philo T. Farnsworth \nhttp://www.ideafinder.com/history/inventors/farnsworth.htm
466625
alexander graham bell- invented telephone
712138
Thomas Edison invented MANY things in his life:\n\n1. Incandescent lamp (aka the light bulb)\n2. Invented the microphone inside of telephones\n3. The locomotive train was a biggie.
1000846
what kind of XM Radio? I think i can help you if i knew more email me: thecoolman@taa.zzn.com
924543
On the radio perhaps?
896657
Nikolai Tesla first had the patents. The carrier wave, amplification, tuning. He didn't finish his working model so Marconi gets credit.\nPoke around the Internet for both.\nNikolai Tesla and Marconi