Here is a site that is trying to get people to vote on the new 7 wonders of the world, but the list of candidates is patently ridiculous. The original 7 wonders were wonders for the scale of the achievement, given the technology of the time. As Michael Williams points out, they left out two of the greatest achievements in history: the American flag on the moon and the Panama Canal. They also left out the first manned space flight, the Manhattan project, and the German WWII fortification of Europe, just off the top of my head. Every one of those projects was a tremendous achievement, dwarfing many of the candidates on the list.
The list includes such relative trivialities as the Statue of Liberty, the Eiffel Tower and the Sidney Opera House. None of those required anywhere near the investment of national capital that a real Wonder requires.