Monitoring system resource usage in Ubuntu is easy thanks to a vaierty of GNOME Panel applets, Conky scripts and Screenlets.
‘Indicator SysMonitor‘ is an indicator-applet that displays CPU and memory usage in the desktop panel (either GNOME-Panel or the Unity panel). It was created by Alex Eftimie (“.deb thumbailer“).
The indicator doesn’t currently provide any features beyond live updating of stats. It’s this ‘simplistic’ approach that will likely chime with some user fed up of bloated, ‘try-too-hard’ applets of similar breed. Its developer is open to suggestions, however.