TI has introduced the TMP103 Digital Temperature Sensor with I2C/SMBUS Expanded Interface.
The device features Multiple Device Access (MDA), Global Read/Write Operations,I2C™-/SMBus™-Compatible Interface, 8-bit resolution with accuracy: ±1°C Typ (–10°C to +100°C). The supply range is 1.4V to 3.6V, and the chip comes in a 4-Ball WCSP (DSBGA) package.
According to the press release the sensor draws a maximum of 1 uA while in shutdown mode and 3 uA while in active mode to extend battery life.
The datasheet is available for download. TI has an evaluation module available for $49.