So, in thinking about Hamlet's book chalange I started looking more closely at how Quicktime handles text.
DISCLAIMER: I haven't actualy tested whether this actualy works in-game yet, as I have no land, and of course the main grid is still down for the upgrade so I can't bug any landowning friends just yet. But according to the Wiki/release notes, if it plays on Quicktime on my comp, it ought to work in SL.
Two ways to do it:
Using Quicktime Pro ($30, downloadable from Apple), make a text movie. Instructions are on Apple's Quicktime website. This is a good approach if you have a good host for the files and the best if you want more than plain text, i.e. adding graphics for a presentation.
Stream the raw .txt file: Just upload your text file to any old webspace and put the URL in your player or media stream. It will play like a movie.
With either of these methoods, you'll want to apply formatting to the text, which can be done using Text Descriptors. By default, Quicktime will calculate the size of the font and window it needs and play a screen of text every one or two seconds, breaking it up by carriage returns (by paragraph). Adding timestamps will cause everything under a particular timestamp heading to be displayed on the screen at the designated interval. Text descriptors also let you contoll basic stuff like alignment, color and special formatting.
Attached: the test file I've been using, which is also a recipie for stir fry. Hey, I had it lying around.