I wanted to test this out, so I reset all my My Data Manager stats to see if anything untoward is going on. Even when I'm connected to wifi, my GS2 still uses the 3G, which I'm a bit surprised about. I get the following 3G usage: Maps (35.4%) Go Launcher ex Notification (17.5%) Samsung Push Service (16.9%) Email (15.5%) Google services framework (13.8%) OS Services (0.7%) I can get my head around the fact Go Launcher ex Notification accesses 3G to see if new SMS etc, but I'm not too sure about the rest. Granted, they are all small amounts of data (<0.1 Mb) but I would imagine this could soon all add up to something more significant. Does anyone know why certain apps require 3G even when connected to wifi?