Advise for moving into a good school zone

Hi folks, looking for advice on public Kindergarten-elementary. We live on the UWS but are just outside of a good public school. I know PS199/87 are having over crowding issues. I'd hate to move out of our rental into their zone and still not get in due to the lottery. Though we would really like to stay on the UWS. What do other people do in this situation? (I've heard that some borrow others addresses, rent a junker for a few months, etc.) We have NO problem moving, would like to be a short walk from whatever school ds goes to, but where/when/how much rent/buy all hinges on where he will go to school. ds will start Kindergarten in Sept 2011. But I believe we have to be in the zone by January '11 and our lease is up this summer, so it's not far away. Thanks in advance.