top

When I run 'top', I see the following:

last pid:   483;  load averages:  0.13,  0.24,  0.42    up 0+02:23:33 22:13:14
48 processes:  1 running, 47 sleeping
CPU states:  0.0% user,  0.0% nice,  0.0% system,  0.0% interrupt,  100% idle
Mem: 95M Active, 24M Inact, 23M Wired, 7616K Cache, 25M Buf, 2212K Free
Swap: 304M Total, 24M Used, 280M Free, 7% Inuse

PID USERNAME PRI NICE  SIZE    RES STATE    TIME   WCPU    CPU COMMAND
455 xfce       2   0 39092K 28700K poll     1:26  1.81%  1.81% evolution-1.4
205 xfce       2   0 47032K 27492K select  34:29  1.42%  1.42% XFree86
483 xfce      28   0  1976K  1068K RUN      0:00  1.98%  0.44% top
291 xfce       2   0 23392K  6100K select   0:30  0.00%  0.00% scilex
227 xfce       2   0 11880K  6548K poll     0:24  0.00%  0.00% xfce4-panel

Q: Why does top show my cpu state as 0.0% when I have 1.42% for X and 1.98% for Ximian Evolution?

A: Those are cumulative CPU utilization figures since the last screen update. Meaning that in your case, Evolution and X are using about 4% of your CPU over the last 3 seconds (if you're using the defaults). Your current "instantaneous" measurement of the CPU indicates that it is spending 100% of its time in the idle loop. The differences are due to the differences in the duration of measurement.

Top has a manual page. Execute the command "man top" at a console prompt to view it.