http://www.new7wonders.com/index.php
You need to cast 7 votes, not only your favourite (read the “How to vote” section).
What happened to the old seven?
They are old, I guess… Not sure of the purpose of this one really… 
None of those make my list. How about the WWW, nanobots and the Mars rovers? Way more impressive than some building.
It’s gotta be the Jamsil Olympic Stadium in Seoul for me.