Hidden away in Apple’s recent release of its new iPhone 4S and the upgraded IOS 5 operating system is Apple’s new iMessage service.  It’s not totally obvious exactly what it is and how it works, so here are some tips and ideas from personal experience:

1. You need to have upgraded the following, preferably in this order:

• iTunes to version 10.5 (on your computer)
• Your iPhone 3GS, 4 or 4S to IOS 5 (by plugging into your computer, then updating via iTunes – click on Check for Update)

• Your device settings (also in iTunes) – specifically your mobile phone number needs to be registered in iTunes – if it isn’t already, you should be able to just enter it next to the “Phone Number” prompt (the format is +61 then your number except for the first zero) as per below.

2. Now, in the Settings > Messages area on your iPhone itself, make sure iMessage is turned on.

3. iMessage works just the same as normal text messaging, using the same iPhone app you have always used: Messages

So now, start a new message and choose who you are going to send it to by touching the “+” button; just as you usually would with an SMS text message. The iPhone automatically recognises if the recipient has an iPhone or iPad with iOS 5, and notifies you of this in the writing field with the greyed word “iMessage”. If it is not possible to send via iMessage so will thus go via normal SMS, the greyed words “Text Message” will show instead.

4. Messages sent via iMessage show up in blue on your message screen, normal SMS’s show up in green.

5. The iPhone will indicate if your iMessage has been successfully delivered to the recipient.

6. iMessage will always attempt to use your wi-fi connection first, then your 3G data connection, and only if those two fail will it send your message as a normal SMS.

7. The recipient will receive your iMessage via their wi-fi connection if connected or otherwise via their 3G data connection – it will be completely seamless to them and will arrive exactly the same as a normal SMS text message.

8. iMessages are not limited to 160 characters like SMS’s are, but remember that if your iPhone cannot find a wireless or 3G data connection it will send it as an SMS instead, and if longer than 160 characters it will split into multiple SMS’s as per usual.

9. If your friend has an iPhone, but you cannot send him or her an iMessage (ie the message screen stays on “Text Message” when you add the recipient, and the sent message is green not blue), then it’s likely (a) the recipient hasn’t upgraded their iPhone to IOS 5 ; or (b) they haven’t properly registered their mobile number in iTunes – the format needs to be +61 then the mobile number except for the first zero. You can instead choose to send the iMessage to their email address rather than mobile number, and as long as Apple knows about that email address they will still get the iMessage on their phone.

Seems complicated but actually it’s not – you might use iMessage without even realising it. There are a few more things to know about iMessage, but I think the above covers most of it.  Quite often now people have mobile plans with unlimited texts anyway, but this is still very cool!  And don’t forget it works on iPad and iPod Touch as well…