From what I can tell, the MacBook does dual channel RAM. It comes with two 256 meg sticks. I wanted more RAM, and I started shopping for it with the assumption, "Apple overcharges for RAM." This has been true since the dawn of time, from what I know, so it seemed safe.
Apple : $500 (upgrade to 2GB on order page)
Crucial: $361 (2 GB kit for MacBook pro)
Newegg : $166 (two SO-DIMMs)
I'm sort of worried that my ability to choose the right product from Newegg was lacking, but I don't know. RAM pricing is so completely insane that it's hard to get a good "This is too expensive/cheap, I know it is the wrong product" feeling.
For the record, I looked for RAM that was:
Maybe I've ordered the wrong thing. Time will tell.