I erroneously ordered som ram for a friend which did not work. I then tried it on my MacBook and now I'm running 3 GB instead of the officially "max 2" supported.
The module I installed is named: VS2GSDS667D2 / Corsair Value Select VS2GSDS667D2 2048MB SO-DIMM DDR2 PC2-5300 667MHz. It works like a charm. More RAM to the people!