Sports Press Pass-How to aquire them?

I recently shot some High school Basketball Final games at a college Gym. I noticed all the photographers had a laynard around their neck with a card attatched. Nobody bothered me and I was allowed to shoot the games but I think I got some evil eyes from some of the photographers. I sell photos online on a smugmug site so its not like I was there just taking up space. My question is should I make my own pass with maybe a blown up version of my Buisness card or is this something I need to buy or aquire. Thanks in Advance