You all out there may be a little sharper than me, but one thing that took me some time to work out is exactly how to create a new Portal listing with HTML content. In the end I worked this out, thought it might be useful to share the code with you:

    Sub AddNews(ByVal Title As String, ByVal ListingText As String, ByVal NewsID As String, ByVal PubDate As Date)
        Dim NewListing As Microsoft.SharePoint.Portal.SiteData.AreaListing
        Dim Audience() As Guid

        If Title.Length > 100 Then
            Title = Title.Substring(0, 100)
        End If

        NewListing = TargetNewsArea.Listings.AddListing(Title, "", Portal.SiteData.ListingType.News, "", Audience)
        NewListing.HtmlBlob = ListingText="BR">        NewListing.URL = "/txtlstvw.aspx?LstID=" + NewListing.ID.ToString
        NewListing.AppearanceDate = PubDate
        NewListing.Update()

    End Sub

 Now as you know, I'm a few "If clauses" short of a case statement when it comes to development, so any more effiecient routines encouraged.