This is so cool, I want to do it to one of the rooms in my house. Ryan Lange and Emily Belden glued pennies to their bedroom floor, and then grouted and clear-coated them.
Some numbers about the project, from The Penny Floor:
1873: the oldest penny used; coin features an indian head instead of Abraham Lincoln
1944: year of the WWII 440 steel penny used because of a copper shortage
59,670: total amount of pennies used
128: total number of man-hours it took to lay pennies
2: total number of people who made the penny floor possible
184: number of reruns (see glossary) placed before grouting
$596.70: total cost of pennies.
$2.55: total cost per square foot x 234sq = 59,670 pennies.
Here’s a short video: