I am using an iPhone (non-3G) and ActiveSync to synch with my corporate Exchange email, calendar, and contacts. After enabling ActiveSync, I no longer had the option in iTunes to synch my calendar and contacts with my Mac through the dock. The only option for doing so was to turn on MobileMe. I want to synch both my corporate Exchange and personal Mac calendars and contacts to the iPhone. After turning on MobileMe in Settings, my access to the Edge network was seriously degraded. The little circle is spinning all the time, the iPhone heats up around where the transmitter/receiver must be, and the battery lasts about 4 hours while I'm doing nothing. My Exchange and Gmail (fetch) accounts are only able to connect and download email once every couple days! Something is definitely wrong with MobileMe access via the Edge network. All these problems go away when I jump on WiFi. Is anyone experiencing the same issue?