Hi Pi_guy1,
Your question about beaches in the NYC Area...
There are two public beaches accessible by NYC Subway: Coney Island and the Rockaways. I don't really like these beaches though.
The nicer beaches are out on Long Island-- Figure a 30-40-minute drive. Jones Beach is a popular place (Take I-495 east to Garden City and get on Meadowbrook Parkway south to the end). Or even further east is Robert Moses Park on Fire Island.
I'm pretty sure you will hook up with lots of Long Islander friends during your course at NYUCD. My sister (class of '00, NYU College of Dentistry) had a blast and frequently had outings with her classmates at the east end of Long Island (the Hamptons). Yes, the farther east you go on LI, the better the beaches.
Central Park is a good place to rollerblade, but do it during the day and don't go there alone at night. For those of you who plan to live in the Upper West Side (the Seinfeld neighborhood), Riverside Park is a good place to rollerblade/jog too. Same safety advice applies.
Good luck, and welcome to NYC!
Tom Hong
Class of '04
University at Buffalo SDM
(Transplanted NYCer)