Basically what I plan to do is to create a simple headphone amplifier which will attach to my Cds photoresistor. The design is visualized below:

The major lame part of my design is that it must be exactly aligned to the target window for it to work as the LASER must reflect back onto the Cds PhotoResistor. Also, the LASER will be red, which is noticeable. I might decolorize my LASER once I calibrate the alignment for sure, perhaps add a LED to denote alignment for live field usage. As for the alignment issue, I am not sure what I could do at the moment. Furthermore, if the window is purposely beveled the device would fail. I might try to aim at a corner of the glass to test possible workarounds. I want to eventually extend this to amplify voice using microphones for outdoor usage and as I design newer versions I hope to make the entire device a pocket size contraption for concealment purposes (it may look like I am listening to an iPod). I would also like to create a durable device that can pass off the transmissions wirelessly, so that I can setup my device and walk away.
If you guys show some enthusiasm I will document my progress and post it here so that you could easily DIY. For the mods or whoever else, if this post seems to sketchy for your standards then feel free to point it toward the sun and FIRE!! Note, this project was inspired by a TV commercial advertising an amplified listening device where an example of its usage was to spy on people across the street.
Go espionage!