array recursion from database rows

Hi. I have a database table I have created for navigation. The table fields are uid, parent_id, menu_name. Each entry is either a top level element with a parent_id of 0 or a child which has a parent_id that relates to the parent uid. What I am trying to do is recurse through a set of rows adding the child(ren) of a parent to a multi-dimensional array. Does anyone know how I can do this, I've tried (unsuccessfully) to traverse the rows to create this array but I keep failing miserably. This is probably very easy for the people on this list so I am hoping someone could help me out. Thanks in advance. Cheers. Bob