Already do. It's called a cellphone with a smallish screen. Basically what you do is not configure email etc and just install a bunch of texting apps. Then you

Already do. It's called a cellphone with a smallish screen. Basically what you do is not configure email etc and just install a bunch of texting apps. Then you simply don't use the web browser etc because you know the thing is now just a tool and no longer a toy.