[neilm]

Your phone should display G, E, 3G, or H in the Taskbar.

When no data is being transferred it will display whatever the fastest throughput is currently available from the current signal from the mast- usually G (standard GSM), E (Edge GSM) or 3G. H will usually only appear if there is a currently active data session, and HSDPA is avaialble. Some operators however now choose to show the 'H' even when data is not being exchanged.

I'm not sure of the reason for the original question about turning off 3G, but the Taskbar indication is irrelevant unfortunately, if saving battery power is the objective. If the Band selection is set to 'Auto' then the phone will always be seeking a 3G connection, even if only GSM is currently available.