I ordered this RAM kit to upgrade my MacBook (Late 2006) from 1GB to 4GB. The speed difference is enormous! Although Apple indicates that MacBooks can only accommodate a maximum of 2GB of this generation, however, are, as can be read all over the internet, definitely 3GB usable. For me, even the full 4GB display.
My conclusion: Absolutely inexpensive way to boost the performance of your Mac significantly.