YourITronics

The circuit seems to be very popular because it is so simple and still has a very useful and practical application and It is considered by some the perfect circuit to get started with AVR microcontrollers.

This thermometer can be used as a standalone thermometer with LCD display or it can be read out with a PC running Linux, Windows, MacOSX or solaris. BSD Unix and others are probably also possible to use for reading the temperatures. No special drivers are needed.

Simple Digital Thermometer: [Link]