Having used 3G on both Nokia 5800 and Nokia E52, here are some points.Both the above have 3 modes (GSM, Dual, UMTS).Selecting GSM is best when you dont have a 3G connection.Dual mode when selected presents a problem and drop in battery life as the handset constanly tries to search for a UMTS/3G signal.UMTS- Again straight forward like GSM, stays put on UMTS, and if there is no 3G signal, your phone does not switch to normal GSM. Used 3G in blr (cellone test SIM) for 10-12 days. Had the same issue(noise) when i enabled UMTS, as the signal level was not all that great.Battery life goes for a toss with 3G