The real fun is when you try and get away from iMessages, it's not quite as simple as it sounds, especially if you also have a Mac.
The other issue I have is people who only have an iPad like my Mother. Even I can't quite see the value in her buying an iPhone, even a second hand one. Hell she just upgraded from her 2G phone
In her case the problem is if I want to send a message to her phone I need to make sure it's on SMS and if I want to send a message to her iPad it needs to be on iMessages. She tends to use whatever is in her hand so I get a mix back from her depending on what she is holding at the time.
I'm actually tempted to create two unique address book entries named "Mum - iPad" and "Mum - Mobile" just to help me keep that in check.
It would be nice if:
A) There was a way that Messages on the iPhone (and Mac) would allow you to combine conversations from the same contact**.
B) Allowed to to quickly switch between iMessages and SMS when sending to that (or any) contact.
**NOTE: I have similar issues with lots of people who have only ever had one contact card AND use iMessages where I end up with two conversations because even though the phone knows who it is it seems to split the chain depending on if it was send to the mobile number or the imessages email address. Be smart enough to combine them... please?