O2 has already reported that the iPhone 3GS launch was a hit for the operator in the UK, but now AT&T is confirming it's been a success in the US too.

In a leaked memo, that you know was just dying to be leaked out, AT&T reportedly says that iLaunch day 2009, as it calls it, "was one for the record books, as AT&T customers scrambled to get their hands on the fastest, most powerful iPhone yet".

The memo, which was subsequently picked up by MacNewsDaily, an Apple news website, goes on to say that the sale of the new iPhone from Apple proved to be:

* Best-ever sales day in our retail stores
* Second-largest traffic day in our retail stores
* Most transactions processed via our IT systems in a single day
* Most upgrade eligibility checks in a single day
* Largest order day in att.com history
* Largest features sales day in att.com history"

In the UK, O2 has already said that the new iPhone 3GS outsold the iPhone 3G on launch day.

The operator, who is rumoured to have also managed to bag the Palm Pre exclusive in the UK, said that footfall to shops on the 19 June was 10 times higher than an average day and the online site saw a 150% increase in traffic.

As a result the handset is currently out of stock from O2 in the UK.