Add Pipe delimeter "|" between each primary link

What do you mean?
Any who are these "much people" you describe?

A 'pipe' has a special meaning on a server, and one which should NOT be used for web requests.
Either way, it's nothing to do with a theme.
What are you trying to say?

Sorry, by 'links' I thought you were talking about the actual URLs, not the rendering of "primary links".
And 'pipes', like I say has a meaning to computer code bigger than just the vertical bar character. Although it's correct to call it the pipe character. Just a bit of confusion there.
Anyway, I posted a tutorial in your other thread.

.dan.

A CSS-only alternative to Dan's PHP/HTML method is this:

#primary li
{
  background-image: url(pipe.png);
  background-position: left center;
  background-repeat: no-repeat;
  margin-left: 5px;
  padding-left: 5px;
}
#primary li:first-child
{
  background-image: none;
  margin-left: 0;
  padding-left: 0;
}

You'll need to create a pipe.png (or jpeg or gif) graphic that has a pipe-looking character in it. And you'll need to play with the margin and padding to get it to look right. Also, IE6 doesn't understand :first-child, so it will display the pipe before the first item (in addition to displaying the pipe between each item) on that browser.