Here is a real fantasy world you can design using electronics and a little programming skills. It is called a 3 dimensional LED cube which is orientation independent. We can display a wide range of low resolution 3-D images and imaginations on this cube. This project has used 125 Leds to design a 5x5x5 cube display. The resolution of the images on display can be improved by increasing the dimensions of the cube. It is smart display which is orientation independent since accelerometers are used to detect the movement of the cube in all planes. This in turn adjusts the display so that it remains upright even if we turn the cube sideways. Microcontroller ATMega32 is also used which interprets the data recorded by the accelerometer and also controls the Leds.
The next attempt is to make provision to control each Led individually without creating a wire mesh. To do so we could connect all of the up and down columns of LED's to the same positive terminal (25 columns total, with 5 LED's each) and then connect all of the horizontal levels to the same 'ground' (5 levels with 25 LED's each). To select a single LED we would apply 5V to the column in which the LED is located and then ground the level that it is on. To display images that have LED's from multiple columns lit we cycle through each column at a fast rate (about 62.5Hz) to make it appear as though more than one column of LED's is on at the same time.
The Led cube is driven by a LED driver circuit which takes input from few of the controller pins and decodes them into something that could control the cube. Also a decoding circuit is employed to control 24 columns using only 5 pins. Visit the Cornell web to fetch in finer details about the system architecture and software control.