Here's some good info:
http://eshop.macsales.com/shop/Memory_Benchmark/Apple_MacBook/
This looks like the best deal. There are several MacBook owners' compliments on the page. I just placed my order:
http://www.newegg.com/Product/Produ...SelectedRating=-1&PurchaseMark=&=0&=100&Page=
Well, I just installed my 4GB ram from NewEgg for $79.99 with free shipping into my May 2007 MacBook 2 ghz Intel Core 2 Duo which is supposed to have a max memory of 2GB and here's the result:
