Do you mean the Resource Monitor?

Click on System, Administration, System Monitor.

A follow-up question for resource monitor - I'm running Feisty on
an AMD 64x2 box. Is there any way to get the monitor to display
status for both processor cores? (seems it will let me select proc0 or
proc1, but not both). Will I need to run two instances of monitor to
watch both simultaneously?

Another option is to place the system monitor on a panel. To do this
right click on the panel where you want to install it and select "add
to panel" from the menu.
Then scroll down to System & Hardware, click on System Monitor, then
chose add from the bottom of the screen. If you then right click on
the new panel icon and choose preferences you will be given options of
6 system resources which you can have continuously monitored on you
panel at all times.

Yes, but in my desktop.
I just founded it. It's name is gDesklets.