Not sure if this will be of any use to you, but I use a code that's been around for years and yes it works with the iPhone.
At the very start of your text message type *0# then leave a space and continue writing your text message and send.
You will get a text back saying that message to number blah blah blah was delivered, it will also show date and time it was delivered.
Delivery does not mean that the message has been read though. It just indicates that their phone will have received the message.
