Guarantors, Gifting, and Co-ops.

As for co-ops, it depends on the particular building. Some allow parents to buy for the children, others do not. Boards are particularly concerned about students who have "no skin in the game" when it comes to being responsible tenants. A board doesn't want to have to track down mom and dad to rectify problems. Other building (see some in the NYU are, for example, are very willing to abide such arrangements. Condos generally have no rules in this regard. Sorry, but for now you are kind of like a pet: some buildings will permit you, others will not.

kylewest, nice line about pets.

pennylane, I've answered this question before on my website. I am sorry the link is so long, but it should still work:

http://www.frontporchllc.com/2008/02/im-going-to-need-my-parents-help-to-buy-an-apartment-in-nyc-how-does-a-co-purchase-work/

ali r.
{downtown broker}