The battery icon shows the remaining battery power. The bigger the coloured section of the icon, the more power.
Further information:
Charge the battery

The battery charging icon shows that the battery is charging.
Further information:
Charge the battery

The 3G icon shows that 3G is available. If 3G isn't available, a different network mode is automatically selected.
Further information:
Select network mode

The signal strength icon shows the strength of the network signal at your location. The more lines, the stronger the signal.

The flight mode icon shows that flight mode is turned on.
Further information:
Turn flight mode on or off

The divert icon shows that all incoming voice calls are diverted.
Further information:
Divert calls to your voicemail
Divert calls to alternative number

The missed calls icon shows that you have one or more missed calls.
Further information:
Make a call
Answer a call

The text/picture message icon shows that you've received a new text or picture message.
Further information:
Read text message
Read picture message

The email message icon shows that you've received a new email message.
Further information:
Read email message

The alarm icon shows that the alarm is set.
Further information:
Set the alarm

The active data connection icon shows that a data connection is active.
Further information:
Use browser

The HSDPA icon shows that an HSDPA data connection is active.
Further information:
Select network mode

The Bluetooth icon shows that Bluetooth is turned on.
Further information:
Turn Bluetooth on or off

The Wi-Fi icon shows that your device is connected to a Wi-Fi network.
Further information:
Connect to Wi-Fi network