Shoutbox

As in many other applications, the whole design is fixed in the GUI. Changing fontsizes globaly will often result in cropped texts, messed up layouts, etc. in many applications.

You could hack MSN Messenger to let it use bigger fonts, but as said, the whole GUI is based upon a certain fontsize. And changing that would mess up everything. (and that goes for many many applications).

A workaround would be, instead of enlarging the fonts, is to buy a big screen (19 inch or so) and reduce the resolution. In that way, everything will be bigger also, but without the loss of Graphic User Interfaces and other things. And Windows will work just as good as before without any special adaptations...

Or, maybe the best thing you can do (but not cheap!) is to buy specialized equipment to view the screen?