Connection speed symbols on my HTC Hero. There are 4 symbols (shown below in order of speed) displayed in the top bar when using mobile network:
G GPRS ~ 56 kbit/s (171 kbit/s theoretical max)
E EDGE ~ 240 kbit/s (473 kbit/s theoretical max)
3G 3G ~ 348kbit/s to 2Mbit/s
H HSPA ~ 3.6-7.2 Mbit/s with current hardware (up to 84Mbit/s on future hardware)