I just installed ProFont on my Debian machine, using this howto. If you’re looking for a monospace font that maintains readability at extra small sizes, ProFont’s for you. On my 1920×1280 15.4″ LCD display (147 pixels/inch), this allows me to stack up three 80-char wide terminals side by side by side, using ProFont at 7 pixels, while maintaining readability. Screen real estate galore!