American tech blog Engadget is speculating that an internal AT&T staff memo leaked to them suggests the timescale for the American launch of the 3G iPhone is between 15 June and 12 July.

AT&T is the operator-partner for the iPhone in the States and the memo requests that AT&T retail employees not take any "vacation" between 15 June and 12 July.

Hyping up the speculation levels is the fact that this is apparently similar to how things worked out with the same memo that went round last year before the iPhone's launch.

The memo, that does not mention the Apple mobile, just says the holiday restrictions are due to "an exciting Summer Promotional Launch".

Apple's Developer Conference starts on 10 June, this is when some pundits believe Apple CEO Steve Jobs will announce the iPhone 2.0, with a launch in June, the year anniversary of the original phone's debut, hotly tipped.