It looks like Active + Wired memory displayed in Activity Monitor should add up to the sum of the real memory used by all processes, but 3.27 GB != ~1GB:
As you can see there aren't really any user applications running, and yet theres more than 2GB of active memory being used. Does anyone know what's going on? Shouldn't the active memory become either free or inactive after an application is closed? Also is the kernel_task process supposed to take up that much memory?
In case anyone is wondering, this a new (less than a year old) Macbook Pro with plenty of hard disk space running Snow Leopard.