In the wp_nav_menu() there are a number of arguments, one of these is:
'link_after' => ,
To add the pipe then:
<?php wp_nav_menu( array( 'theme_location' => 'primary', 'link_after' => '|' ) ); ?>
If you want to style it padding or margin add a class and a style:
<?php wp_nav_menu( array( 'theme_location' => 'primary', 'link_after' => '<span class="my-span">|</span>' ) ); ?>
Twenty Eleven style.css changes, remove the 1.2125em padding and add a margin.
#access a {
padding-right: 0;
}
.my-span{
float:right;
margin-left: 1.2125em;
}
This solution is only the same height of the text, problem is child item also have the pipe!.
For other readers css version:
To make it menu height then add to style.css, this is based on twenty ten or twenty eleven.
#access li {
border-right: solid 1px #ccc;
}
HTH
David