TMP 36:
The TMP36 is a low voltage, precision centigrade temperature sensor. It provides a voltage output that is linearly proportional to the Celsius temperature. It also doesn't require any external calibration to provide typical accuracies of ±1°C at +25°C and ±2°C over the −40°C to +125°C temperature range. We like it because it's so easy to use: Just give the device a ground and 2.7 to 5.5 VDC and read the voltage on the Vout pin. The output voltage can be converted to temperature easily using the scale factor of 10 mV/°C.
Got this one from Sparkfun.
Link to datasheet.
- Voltage Input: 2.7 V to 5.5 VDC
- 10 mV/°C scale factor
- ±2°C accuracy over temperature
- ±0.5°C linearity
- Operating Range: −40°C to +125°C
DALLAS DS18B20 18B20 TO-92 Temperature Sensor
- 1-Wire Interface Requires Only One Port Pin for Communication
- Each Device Has A Unique 64-Bit Serial Code Stored In An On-Board Rom
- Requires No External Components
- Thermometer Resolution is User Selectable from 9 to 12 Bits
Got from this seller's Amazon listing.
AM2302 DHT22 Temperature and Humidity Sensor Board Module
Arduino tutorial from Adafruit.
See Raspberry Pi hacks book for example usage.
