I am going to America soon and I am keen to avoid data roaming charges, having read some horror stories about iPhones in this regard.

The phone will be in flight mode most of the time, but I will be switching it on to send some texts. I will also be using it for wi-fi access.

Here's what I intend to do:
- Switch off data roaming
- Switch off 3G
- Switch off notifications
- Divert all calls so that I avoid voicemails

Do I need to do anything else?

Thanks.

nope, that should do it

The major thing to make sure of is that data roaming is switched off.

The rest is only paranoia if you really don't want to receive incomming text messages or phone calls.

Visual voicemail relies on data, so won't work when you have data roaming turned off, so calls going to voicemail will just cause an SMS to be sent to your phone telling you there is a message.

I took my iPhone to the US for two weeks last year, and even with data roaming turned off, it still racked up some roaming data - about £1.70 in two weeks due to a bug in the older software. O2 promptly refunded this for me.

Everything else was fine and dandy. No need to worry really.

Depending on the network, you may be charged for diverting voicemails (cost of receiving the call + cost of diverting it back to the uk) even if it's set to "divert all". Check with your network and have the voicemail switched off if you want to avoid it.

do you get charged for receiving texts?

The iPhone 4 (and other iPhones running iOS4 when it launches on Monday) has an extra feature.

Next to the Data Roaming option, there will also be an additional option to turn cellular data off ALTOGETHER.

That's all you need to turn off, don't worry about anything else.

Sorted.

On O2, receiving texts whist roaming is free.

Receiving a phone call is £1.03 per minute. Making a call to the UK from the US on O2 is £1.37 per minute, and sending an SMS is 25p.

A permanent call divert to answerphone should be done at the network level, therefore not incurring any roaming charges, but check with the network operator.

Damn, I fly one day before the new OS is released!!

I don't intend to answer any calls, so might it be best to just get the voicemail switched off completely?

That's what I thought, but currently T-Mobile say they'll charge. Best to be safe...

Though T-Mobile are removing voicemail charges in the EU from this summer.

Makes no difference while you are roaming - the switches basically do the same thing if you are (prevent cellular data). The new switch just does the same thing when you are in the UK as well.