Hold up people with your answers.
He said its a Macbook Pro 3,1 which is the older body style with one dvi port. This is not the newer unibody with mini display port.
All you need to hook up to a 30 inch display is a dual link dvi cable. That is all, no adapter is needed with that model. It supports the 30 inch models from dell or apple(apple's monitors just have a built in cable).
Also, apples 20 and 30 inch monitor are dvi based monitors and the 24 inch LED one is the one that uses the mini display port.
Dell sells two 30 inch LCD's and they have a few different options:
I use the exact setup you have with the dell 2709W 27 inch and it works great. I love Dell's Ultrasharp LCD lineup.
http://reviews.cnet.com/4520-10442_7-6470175-1.html apple 30 vs dell 30