I upgraded my 6 year old MacBook Core Duo with a 120GB SanDisk Extreme SSD. The results are pretty incredible considering the age of the computer.
The only problem I'm having are intermittent stalls. It's happened during tasks like using a simple text editor, to browsing, to watching videos, to just sitting idle. All of a sudden the cursor changes to the dreaded beachball and the system becomes completely unresponsive, except for being able to move the cursor.
Anyone have any ideas how to fix this?