yes PJ darling... if you're there and its still before the advertised end time and all equity homies have been seen, they will see non-eq... but don't worry, i believe there will be open calls for Hairspray (assumed this was in light of the recent playbill calls for ECC dancers for HS).
Yes, it's called "crashing." If you show up early on and wait around, they'll probably fit you in someplace, although it may be a while. Also, at the end of the day, they'll sometimes set aside time just for non-Eq's.
There should be a sign-up sheet for what AEA terms "Future Members." It allows you to audition given any extra time at the end of the scheduled Equity member call and is first come, first served. It just means you have to sit patiently and wait for the possibility of an opening, so bring a good book or a fully charged iPod, it could be a while!