Temperature Sensor DS18B20 digital

• Usable temperature range: -55 to 125°C (-67°F to +257°F)
• 9 to 12 bit selectable resolution
• Uses 1-Wire interface- requires only one digital pin for communication
• Unique 64 bit ID burned into chip
• Multiple sensors can share one pin
• ±0.5°C Accuracy from -10°C to +85°C
• Temperature-limit alarm system
• Query time is less than 750ms
• Usable with 3.0V to 5.5V power/data

http://bildr.org/2011/07/ds18b20-arduino/