I was previously running my SR 2.2 GHz Macbook with the standard 1GB RAM before I upgraded today to 4GB G.Skills from Newegg. I noticed that not only did the system become smoother but the CPU became cooler and the fans were not running as high as they normally would in simple tasks such as movie watching or Windows XP virtualization. To test this, I opened Word, Photoshop CS3, Safari, Windows XP via Parallels, and an avi movie on VLC player only to notice the CPU temperature was maintained below 60 C with steadily low fan speeds. Has anyone else experienced this? Also, does anyone with 4GB configurations still occasionally experience the rainbow beachball when using Safari 3 in Leopard? It happens very occasionally for me now and I was wondering if it's normal. Nevertheless, I'm very happy with my upgrade. If anyone is looking to upgrade their SR Macbooks or MBP's to 4GB RAM, I highly recommend these: http://www.newegg.com/Product/Product.aspx?Item=N82E16820231135 They are now even $5 cheaper than when I purchased them last Friday.