i HAVe heard that you can control lighting from a comupter. How can i do this (If you can)?

You might want to checkout smarthome.com.

One example of a computer control lights option:
http://www.smarthome.com/_/ProductR...

The lighting control referred to by aegis is the x10 system. You can also control appliances or any device that uses a standard outlet. Lighting controllers can also control brightness (incandescent lamps only). X10 controllers are interfaced through the serial part, rf, telephone, and I believe USB. There is also a system that uses MIDI signals used mostly for theatrical lighting and special effects. There are at least two other systems used for building power control. The x10 system is the cheapest with modules starting at about $10.