[Lynne]

That probably is the easiest way. This works for my simple field of comma separated items (I tested it on my field16, you need to change for yourself):
postbit_display_complete

PHP Code:

if ($post['field16'])
{
$find = ",";
$replace = "<br />";

$post['field16']= str_replace($find, $replace, $post['field16']);
} 


Of course, also add the field to your postbit.