Sure, there's 'System Monitor' in System/Administration/System Monitor. It does what you want.
To get Ctrl-Alt-Del-shortcut to open System Monitor do this:
1. Open Configuration Editor (hit Alt-F2 and run gconf-editor).2. Browse to apps/metacity/keybinding_commands3. Set the command_1 to gnome-system-monitor.4. Browse to apps/metacity/global_keybindings5. Set run_command_1 to Delete
That's it :)