There have been other (non-blackberry) data devices (HP iPAQ and HTC TyTN are good examples that come to mind), that have had the WiFi function available but there incidences of accidentally switching over to the GPRS/EDGE/UMTS/HSPDA network occurs when for whatever reason the WiFi network slows or the connection is severed.

The problem on these devices is that the device doesn't notify when this switch happens (therefore data usage on the device starts accumulating). Is there some type of notice given to the user when the switch goes from WiFi to GPRS/EDGE/UMTS/HSPDA?

Thanks,
--Phil