SAR

The SAR, or specific absorption rate, of a mobile phone is the amount of RF energy it exposes its user to. In the United States, mobile phones need to have a SAR rating of 1.6 watts per kilogram (W/kg) or less. In Europe, the limit is 2 W/kg. While there have been plenty of studies that conclude that phone based RF radiation is harmful, there are an equal amount that find the opposite to be true. In any event, a device with a lower SAR rating will pose less of a risk than one with a higher rating.

S90

S90, previously known as Series 90, is the software platform that Nokia runs on top of the Symbian OS in its 77xx series of touchscreen enabled multimedia devices. Nokia has announced that S90's functionality will likely be folded into the S60 platform, and that S90 will cease to be developed.

OLED

OLED is a newer display technology that creates displays that are less power hungry than existing LCD technologies. OLED displays are more efficient than LCD displays because OLED pixel sites use organic materials that produce their own light, removing the need for a backlight. Currently OLED devices are still somewhat prone to performance degradation over time, which is one of the reasons they have not replaced LCD displays on a wide scale in mobile devices.