Not quite true Astin and here's why.
The apparent diameter of mars varies depending on where it is located in it's orbit relative to Earth. At a normal conjunction it has an apparent diameter of around 17.9 arc seconds, however for the current 2003 conjunction the apparent diameter was 25.11 arc seconds.
Physical diameter (arc seconds)
Mon 25/8/03: 25.10 arc seconds
Tues 26/8/03: 25.10 arc seconds
Wed 27/8/03: 25.11 arc seconds
Thurs 28/08/03: 25.10 arc seconds
Fri 29/08/03: 25.09 arc seconds
Sat 30/08/03: 25.07 arc seconds
Sun 31/08/03: 25.03 arc seconds
The apparent change in brightness was from -2.8 to -2.9 at conjunction and back to -2.8 at present. For naked eye and small telescopes a negligible change in brightness that most observers are NOT capable of detecting without a photoelectric detector.
Cheers,
Ian