Circles and cylinders
Péter has been experimenting on how to create that elusive form - circles - from our traditionally square LEGO bricks. Over time his collection has grown, and he has documented his finding in this flickr album.
The forms could be very useful for building LEGO spaceship engines and detailing, towers and other architecture, and in many other applications. Most of them can be extended to create cylinders of the height you need. Very inspiring!