Cor, he wasn't asking how to use focus, he was asking how to use the keyboard and make it popup when an item does take focus. I've seen it but can't remember where it was. You can even choose whether to make letters or numbers and symbols appear. Erel ... help?
The user can also hide it by pressing on the "Done" key.
This is the regular behavior of Android.
If you like to not show the keyboard at all then you should change the InputType to none.
It is possible through Android's InputMethodManager. You would have to use AGraham's reflection library to access it, which can be frustrating if you're not a Java coder. If AGraham sees this thread he will be able to give a code example of how to do it.