MizBlue you can contact 7th on Sixth about volunteering, but I heard many of the slots go to students at schools in the nyc area (Parsons, Pratt, FIT, etc).
I went to a few shows last February (FW04)...I wrote the PR companies of the designers and told them I was a student in SF and was working on my thesis (which is a magazine; I wanted to write an article on the shows for it). You can also show up at the tents/location, make nice with security, or talk to the PR people. I got a ticket to Marc Jacobs last year by talking to a PR person who was holding the tickets. One of the people didn't show up, and I got to go in with her. Of course I was waaaaaayyyyy in the back (standing room), but that's ok. It was a great show (and wonderful for star-watching).
Kimkhuu Some designers do multiple presentations...Donna Karan is showing at 3pm and 4:30 on Friday 2/11 and Ralph Lauren is showing at 9am, 10am, and 11am.