it's different for every school, but most PA schools require either the MCAT or the GRE, and all require you to have clinical experience before applying. I know that Duke requires 500 hours of patient care before applying, but I"m not sure about others. Check out the websites for the PA schools at Duke, Emory, George Washington, and MCG for more info.
I applied last year actually to Cornell and some other NY school. These were the only two schools in NY that DIDN'T require gre/mcat. I got into the second school but they required me to take one pre-req class I was missing and I wasn't sure cause I might get into medical school...blah blah..so I declined.
Then I was invited to an interview at Cornell but I cancelled it (claimed I had a family emergency and had to leave the country)because the PA classes started in April....and I didn't want to start and have to drop out because I got into medical school a month later. I shoulda started cause now, I still have no acceptance to med school.
If this medical school didn't work out then I might re-apply to cornell. At least I was good enough to be invited for an interview.
Oh yeah, I already had my BS degree so I only applied to programs that would give me masters in PA....