Click on the embedded video to watch how these speakers are made, and to see a demonstration of their effectiveness. If the embedded video does not show up for you (this is usually the case for at least a few people) just click this link: DIY Phone Speaker Video
Step 1: What You'll Need
Two cheap plastic cups (solo work great), a roller cover, a box cutter and a marker.
Step 2: Outline Your Phone
Trace an outline of the bottom of your phone in the middle of the roller cover. This will work best with a black marker.
Step 3: Cut the Outline
Cut out the outline of your phone. I used a box cutter after realizing a small X-acto knife wasn't going to get the job done.
Step 4: Trace and Cut Holes Onto Your Cups
Using the roller cover, trace holes on the lower portions of both plastic cups. Cut out the holes with your box cutter.
Step 5: Put It All Together
Slide one cup onto either end of the roller cover. Now you're ready to party! Watch the video embedded in the intro if you'd like to hear the difference between my iPhone using just it's built in speakers VS when attached to these ones. In the video I also demonstrate how the speakers are made, and the entire thing is less than a minute long. Enjoy!
Here's a link to the video again incase the embedded video doesn't show up on your computer: DIY Phone Speaker Video