Is a N95 mask at all useful in a fire to cut down on the smoke?
I do not think it would help with anything but the smoke itself, but would it do a good job for that at all?
Our unit secretary had a BAD time with the smoke the last time we had to evacuate the building (10 flights of smoke filled stairwell) and was thinking about giving her on of the ones that I keep in my bag here at work just for that purpose...

Before anyone asks, that was a weird and freakish fire...
The power company was working on the lines out front and swears that they had nothing to do with it(sure...)
But we had a gigantic power surge that caused our backup generator to catch fire(This is a HUGE one, about as big as a small panel truck). That set the backup-backup generator on fire( <img src="/images/graemlins/ooo.gif" alt="" />), and that set the backup-backup-backup(yes, we have a backup to the backup to the backup generator!) that is dedicated to running the lights and ventilators for the stairwell(it was a fallout shelter back in the day...) This caused the stairwell to FILL with smoke and be pitch black as well... NOT a good thing in a 20 story building...
Thankfully, I was there with the 5 flashlights I carry on me at all times... <img src="/images/graemlins/grin.gif" alt="" />