Okay, now this is a bit disturbing: XianLi of Hackint0sh.org proved that Apple tracks all stock and weather updates via your iPhone's IMEI. I have no idea why it would be necessary to track my weather habits, let alone the stocks I'm tracking.
"As I sit here applying a new layer of Reynolds tin foil to my international hat of conspiracy, its been proven that Apple tracks iPhone usage and tracks IEMI numbers of all their iPhones worldwide. Hidden in the code of the “Stocks” and “Weather” widgets is a string that sends the IMEI of your phone to a specialized URL that Apple collects."
You can't get stocks or weather information if you attempt to hide your IMEI. Very interesting; there's some discussion at slashdot.org as well.