There's this nifty little program called tpp for the Linux terminal, which turns a simple text file (with minimal syntax) into a full scale powerpoint-style presentation.
Make a new slide with --newpage texthere. Make a header with --heading texthere. Make blocks of text appear using --beginoutput and --endoutput.
I made a tiny script for commands with urxvt so that the font is bigger and prettier, using the Gentoo Wiki:
urxvt -name Terminal -fn "xft:Droid Sans:pixelsize=20" -fade 20 -depth 32 +sb -fg white -bg rgba:2000/2000/2000/dddd
And then I run tpp filename and tah dah, I have a better Powerpoint than anything the Powerpoint program could ever offer.
Now to work on getting an external monitor to display my text!
Also, the original version of my script above uses urxvtc instead, because if you stuff "urxvtd &" into your fluxbox startup file, and use the urxvtc command instead, you can get a daemon/client interaction that saves time and memory.