I used a plastic coffee can for the sounding tube by removing the lid and cutting a large hole in the bottom. The vacuum form of the can's bottom gives a perfect template for cutting a nice, large round hole while leaving a lip around the bottom edge.
Step 2: Visualizer Reflector Membrane
Cut a latex glove into a section large enough to cover the top of the can. Secure the membrane to the top of the can with a rubber band. Pull the edges of the membrane until the membrane surface is taut and even. Trim away the excess if you want to be neat... =)
Step 3: Membrane Reflector
A fancy way of saying, "Paste a mirror in the center of the membrane". I used an old CD and scissors to cut the size I needed (yes, I am cheap!).
Step 4: Continuing the Excellence of Cheapness!
Use a coat hanger and pliers to bend the wire into a holder for your Laser Pointer. You want it to reflect down onto the mirror at a sharp angle for reflection off the cieling.
Step 5: The Visualizer Driver Element!
Otherwise known as a cheap auxilary speaker like you can buy at Radio Snack or find at a garage sale that has a mono jack. Remove the top cover of the speaker, then superglue the bottom lip of the coffee can assembly to the speaker edge.
Step 6: Final Check!
Make adjustments in the coat hanger holder until the pointer beam lines up nicely with the mirror. Placing the speaker on top of the wire base works wonders. Now plug the mono jack into your PC output, cue up your favorite tunes, and get ready for the show!