These two contribute to a wonderful, fast, two-channel analog-to-digital converter, which can be utilized in a number of situations where high-speed (108ksps) data acquisition is necessary
http://www.semifluid.com/PIC18F2550_MAX144.html
The MAX114 is an 8-bit four-channel ADC that allows for up to 1Msps (1,000,000 samples per second) with a parallel 8-bit microcontroller interface.
http://www.semifluid.com/PIC18F2550_MAX114.html
The MAX187 is a 12-bit A/D converter. You can create an interface to this ADC using serial data communications techniques. Analog-to-digital conversion and data transfer from MAX187 require only three digital-I/O lines. You can create a simple interface b
http://www.edn.com/article/CA307869.html
provides 19-bit resolution
http://www.edn.com/article/CA196483.html
inexpensive 10-bit A/D converter with the added capability of measuring the temperature of the IC and the value of the nominal +5 V supply
http://www.phanderson.com/printer/ltc1392/ltc1392.html
http://www.edn.com/archives/1995/101295/21di5.htm
http://www.bobblick.com/techref/projects/a2d555/a2d555.html
For this this project you can either choose to use the MAX186 or the MAX187. The code examples for this article are for Basic Stamp II.
http://www.gorobotics.net/Articles/Microcontrollers/A-Simple-And-Free-ADC-For-Your-Microcontroller/