There's a really interesting article on DRB with a load of images of architect/designers concepts for future Mega-structures. Lets hope that some of them will actually be realised and not just remain as a 3D concept inside a computer.....
This design by UK architect Yheu-Shen Chua has been awarded Third Place in eVolo's 2011 Skyscraper Competition: "One of the main purposes of the project is to allow the water from the upstream river to engage directly with the visitors through a series of containers.
Belgian Architect Vincent Callebaut dreamed up a combination of skyscraper and airship, where the skyscraper itself floats in the air, feeding on a green "algae" energy: the "Hydrogenase" project is as eco-sustainable, as it is beautiful
Strange combination of a tree-like skyscraper and huge Zeppelin airship-inspired floating observation decks is a radical vision by Romanian Dorin Stefan Birou Arhitectura
Another alien creature-like Taipei concept is proposed for the Performing Arts Center, by B+U design
Algorithmic Architecture! More than just a catchy term, this is a great tool in coming up with organic and nature-inspired forms, based on mathematical algorithms