Dude, Edit->Preferences->Appearances->Fonts and set
the minimum font size to about 12 or 14. Problem
solved. You are using a recent version of
Mozilla, of course, right? Most of the previous
user's complaints can be solved too. The one thing
Moz doesn't do yet is scale images down to prevent
the need for horizontal scrolling. There's a bug
filed on that, but it hasn't been fixed yet.