On eVolo Architecture you find amazing ideas for buildings.
Here are some images from the 08 Skyscraper competition.
First place: Elie Gamburg
Second place: Rugel Chiriboga - Ted Givens
Third place: Alberto Fernández - Susana Ortega
Competition mentions: Christopher Talbott - George Tolosa, Daekwon Park, Tingxing Tao, Sohta Mori - Yuichiro Minato, Claudiu Barsan-Pipu - Oana Nituica - Irina Dragomir - Bogdan Ispas and Natalie Ghatan.
Visit eVolo for more images and previous competitions.
Wondering what CAD software they used for the different projects?