Wow, safari is not very 'thin' then. I've got mozilla (for a couple days, 15 tabs), thunderbird, mail, notes, itunes, calc, and a few terminal instances open and I've only got 1.9GB listed as active.All I have is safari open and I'm using almost 2GB of RAM. If the OS sees the ram it will use it. If it doesn't see the RAM it will be more lets say "stingy" with what it puts there from what i have seen. When I had 2 GB in Mine would look similar to yours Zoolook.