I am still relatively a new Mac user (5 months so far). As per my sig specs I have 4g RAM in my MacBook. I use istat and I am always aware of my RAM usage. After I installed FF3, I noticed my RAM usage has gone way up. I also tried FF2 after and it still was up in usage. Even when I have FF closed I still have 1g of RAM being used. I then noticed in activity monitor that kernel_task is using 232 mB of RAM right now. What is it and what is it doing? I have installed ONYX and cleared all caches, etc... It seemed to have help for a few hours, then the RAM usage has crept back up. Normally, with FF2 open I still would have maybe 3.2 of free RAM. I'm not sure if I'm missing something or is this normal? Any thoughts?