On our SBS2003 box, we sometimes have sql instances using upwards of 1.5Gb ram. The machine ram usage goes beyond the available physical ram, and the machine slows to a crawl.
We've used this technique to reduce the sbsmonitoring instance and the ssee instance.
There is also a nice tip there for using taskman from the cmd line to get the sql instance. Of course Process Explorer also will tell you this info directly.