Dim lbs As New List(Of ListBox)
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
        lbs.Add(ListBox1)
        lbs.Add(ListBox2)
        lbs.Add(ListBox3)
        lbs.Add(ListBox4)
        lbs.Add(ListBox5)
 
        Dim nlb As Integer = lbs.Count
 
        For i As Integer = 0 To nlb - 1
            AddHandler lbs(i).SelectedIndexChanged, AddressOf _
              ListBox_SelectedIndexChanged
            For j As Integer = 0 To nlb - 1
                lbs(i).Items.Add("item" & j.ToString())
            Next
        Next
    End Sub
 
    Private Sub ListBox_SelectedIndexChanged(ByVal sender As Object, ByVal e As _
      System.EventArgs)
        Dim slb As ListBox = CType(sender, ListBox)
        Dim item As String = slb.SelectedItem.ToString
        If slb.Tag IsNot Nothing Then
            For Each lb As ListBox In lbs
                If lb IsNot sender Then
                    lb.Items.Add(slb.Tag)
                End If
            Next
        End If
        slb.Tag = item
        For Each lb As ListBox In lbs
            If lb IsNot sender Then
                lb.Items.Remove(item)
            End If
        Next
    End Sub

Those people who think they know everything are a great annoyance to those of us who do - Isaac Asimov