How do I make an Audio Sensor?!?

I am making a project that requires an audio sensor. I need my arduino uno to be able to register a short burst of loud noise. Could someone please give some advice as to what mic. and amp to use. Parts lists and schematics would be very helpful. Thank you.

http://arduino.cc/en/Tutorial/Knock

I've been using a piezo like that says, but it has a hard time registering sound, any advice to make it more sensitive or to amplify the signal?

https://www.sparkfun.com/products/9964 ?

Is there a way I can make this 100x amp with an op amp chip? If so could you please post the schematic or name of the type of amp?