Render a typed text to a texture: what is the best way ?

I'm looking for a way to write text on a texture, and then render it on a screen: in the game it's just the screen of a computer where a scientist is typing text on.

do you mean that it writes letter by letter like he is typing, or just static text; if it is only static text, you can make a material that is a 'decal', make the first texture the one you want as your texture and the seconds one as the text, but you'll have to make a texture of the text, you can't use a GUIText or anything as far as I know.