FF has a minimum font size (under the advanced button) which affects every font, regardless of how it is set. "zoom" is overrated, but available for most browsers via plugins.
Slim Server is an excellent way to stream music over a network from a central store (or even over the internet).
VLC can play movie files from another PC on the same network.
Windows Media Player 11 is supposed to have network streaming capabilities as well, but I'm not sure if you have to access it from a PC with windows media center or not...