I just get a constant analog reading of 880....
You should get a reading of around 512, but that need not be important. Maybe its just got a slightly high bias. Have you checked with a scope, or other test (speaker, AC meter, arduino test program...), that it doesn't react to sound?
I think Si's schematics should work. You can also try my one-transistor variant that I used on my morse encoder/decoder
. I think the 3904 should work instead of the BC548 I used, but thats mostly a guess, I haven't really checked.
Both schematics just amplifies the soundwaves, and will oscillate around the center value (maybe 880 in your case). You will have to make some threshold value in software to check against. It's the same thing I did with my morse decoder btw, it just checks for sounds for its audio input. A simple clipping filter, I just ignored any samples below a certain value.
Other that that, why not use an op-amp? It seems well suited for your purpose, easy to make the amplification / sensitivity variable and much more sensitive than the aforementioned circuits.
A few links here for some inspiration:http://www.discovercircuits.com/M/mircophone2.htm