I've just signed up for the ical beta and it tells me I must have ios4.0 on my iphone. This is all fine except i have an iphone 3G (like alot of people) and ios4 runs like a dog on the 3G. I (like many) downgraded again to 3.1 and it runs like a dream....most cheesed off to be forced to upgrade to an ios that kills the phone!...Cheers Apple!