I just moved into a new place in a city and with my bedroom being on the ground floor I am getting a lot of street noise. I was wondering if anyone had some tips on how to get some easy sound reduction out of my current windows (double pane) without replacing them or spending too much. Any help would be welcome, but I'd really like to do this without too much work.
Also, does anyone know of a good type of drape to use to reduce some of the noise?
Thanks!

Yes, there is a science to this. If you get the right type of double pane glass, it will reduce most sound dramatically.

There are three ways to do this with the window:

Secondary glazing of laminated glass on the existing glass.

Double pane glass. The wider the air gap, the more sound insulation.

Double pane glass with two different glass thicknesses to interfere with the sound waves.

More info here:
http://www.windowstoday.co.uk/sound-insulation.htm

http://www.allaboutdoors.com
http://www.doorandwindowparts.com