$ perl -e '$0="my really awesome process name"; sleep 60;' &
[1] 73413
$ ps
  PID TTY           TIME CMD
70164 ttys002    0:00.05 /opt/local/bin/bash
  677 ttys004    0:05.06 /opt/local/bin/bash
73413 ttys004    0:00.03 my really awesome process name