CPU History Window
Each time the CPU% bar in the main Peek-a-Boo window gets updated, the CPU history graph is also updated. The graph moves slowly to the left.
When you open a CPU History window (from the Processes menu, or press Cmd-U), a window like the above window will open for the selected process. This information is stored, so in the future, Peek-a-Boo will periodically check to see if that process has been started and, if so, it'll pull up its CPU History window to track CPU usage. To make Peek-a-Boo forget about a given CPU History window, close the CPU History window. Then Peek-a-Boo won't include that window in its periodic search any more.
You can open several CPU History windows for the same process. While this isn't terribly useful for normal Macintosh use, it can give a marvelous hi-tech feel to your Mac if seventeen history windows are plastered at random intervals on your screen.
Peek-a-Boo ST includes the ability to show CPU history windows as "Techie" CPU Windows. This makes the windows look a bit different -- a dark background with an oscilloscope-like line. To move these "techie" windows, just click anywhere on them and drag them to their new place. You can turn "Techie" CPU Windows on and off in the preferences dialog.