RAM for the new Powerbook 1.5 ghz

I just ordered one of the upgraded powerbook 17" and I kept the RAM stock at 512mb because it is expensive to get it from Apple. Anyone have any suggestions on where I can get the RAM for this powerbook for cheap? A friend of mine mentioned something about internal ram and external ram, does this apply with the powerbooks? Can I add without having to remove?

The only other upgrades I made were, graphics card up to 128mb and hard drive up to 5400.

well, corsiar is good, crucial is good.....those are the best from what I've read and heard...you can't really go wrong with either. I have corsair, and they have a lifetime warranty...or they did when I bought mine....

A good place to order from is newegg.com. I've been buying from them for quite some time and they always deliver within a day or two to Illinois. As a matter of fact, I just ordered 2 512 sticks yesterday for my new 15 PB. With shipping it came to $260.00 for Crucial. I think the corsair was $118.00 each plus shipping.