EDIT: This makes it sound like I hate my job or something. I don't. I enjoy my work. I simply enjoy my family more. I'd prefer to go to the office, work hard for 8 hours, then come home.
Never made it to the prototype stage. After watching the Mythbusters try this trick, I'm kinda glad the poor guy didn't spend the time.
Fresnel lenses. Better alignment. Much more reliable.
Science is fun!
The Google version looks more professional, though...
Title 18 United States Code, Section 331
Whoever fraudulently alters, defaces, mutilates, impairs, diminishes, falsifies, scales, or lightens any of the coins coined at the mints of the United States, or any foreign coins which are by law made current or are in actual use or circulation as money within the United States;
Whoever fraudulently possesses, passes, utters, publishes, or sells, or attempts to pass, utter, publish, or sell, or brings into the United States, any such coin, knowing the same to be altered, defaced, mutilated, impaired, diminished, falsified, scaled, or lightened -
Shall be fined under this title or imprisoned not more than five years, or both.
For an interesting explanation of why it is now illegal to melt pennies and nickels see: