The buzzword in cell telephone circles is 'dual band.’ This refers to phones that can connect via the 900 and 1800 MHz frequency bands currently used in China.
The phones automatically search out and utilize the clearest frequency giving you optimal reception.
The following manufacturers retail dual band phones in Beijing, listed below with model numbers and retail prices:

Ericsson S868 (¥1580)
Motorola 928 (¥2480)
Nokia 6150 (¥2800)
Phillips 898 (¥2500)