List of Parts:
Condenser mic cartridge (I got mine from the component bins at Radio Shack)
10.0UF/100VDC metal-poly capacitor
1000PF 100V ceramic disc-style capacitor
9V battery snaps
2.21K ohm 1/4W 1% metal film resistor
Male XLR plug
9V battery holder
Casing for the mic (I used a Zhena’s Gypsy Tea tin)
Heatshrink tubing (optional, but can help prevent shorts)
All parts can be found on DigiKey.
Originally posted this (along with the schematic) on my blog. You can contact me there if you have questions.