Text Message

Hello,
How can I make an object produces a text message?

I am not trying to make a game this time, instead I am making a guide to my lecture.
For example I am going to design a room filled with some decorations and where a boy standing inside beside the bed and produces a message like “Hello, the objective of this lecture is to enable the students to know the different types of Greetings.

This could be useful:

http://wiki.unity3d.com/index.php?title=ObjectLabel

With some sort of switch to turn the label on/off. Such as on click:

Or you could add some 3d text objects into the world and switch them on/off like above.

Karl