Mr. BroHogan,
Thank you for your nice comments.
You must have put quite a bit of work (and skill) in that beautiful cherry wood case. I myself used an empty box of Ferrero-Roche chocolates. Another case I am thinking of using is a glass dome, usually used for displaying pocket watches (I bought one from ebay, did not receive it yet).
The good thing about using 74HC595 is the price. The bad thing is that most of the digital outputs are used, there is no room for other add-ins like an ethernet card (for wi-fi I am going to use the serial communication pins).
I have to do the I2C memory, indeed. And I can load it with a book of quotations (256K would cover aprox 128 book pages), for example.
As for the VU meter, check out this chip, MAX7400 (see http://datasheets.maxim-ic.com/en/ds/MAX7400-MAX7407.pdf) that filters audio frequencies based on the clock signal. I did not test it yet myself (I just ordered a sample from maxim). According to specs, filtering should be handled through software.
I am thinking of a novel solution for the power supply. Even though the whole rig takes an average of 15-20 mA, the set of 4 AA batteries dies out rather quickly, in about 20 hours. If I want to add the wireless, they will last much shorter. I am thinking of hanging the whole box from the bulb socket in the ceiling, and eventually make it to rotate (with the remote, of course) for the best reading.
Nice brainstorming session you started here. Thanks. You really stimulated some ideas. I will keep you posted.
PS Wow! If I get it hooked to the bulb socket, then I can also have some X10-based functionality available.