Sample 1: Delete duplicate items in a single list

Sub DelDups_OneList()
Dim iListCount As Integer
Dim iCtr As Integer

' Turn off screen updating to speed up macro.
Application.ScreenUpdating = False

' Get count of records to search through.
iListCount = Sheets("Sheet1").Range("A1:A100").Rows.Count
Sheets("Sheet1").Range("A1").Select
' Loop until end of records.
Do Until ActiveCell = ""
   ' Loop through records.
   For iCtr = 1 To iListCount
      ' Don't compare against yourself.
      ' To specify a different column, change 1 to the column number.
      If ActiveCell.Row <> Sheets("Sheet1").Cells(iCtr, 1).Row Then
         ' Do comparison of next record.
         If ActiveCell.Value = Sheets("Sheet1").Cells(iCtr, 1).Value Then
            ' If match is true then delete row.
            Sheets("Sheet1").Cells(iCtr, 1).Delete xlShiftUp
               ' Increment counter to account for deleted row.
               iCtr = iCtr + 1
         End If
      End If
   Next iCtr
   ' Go to next record.
   ActiveCell.Offset(1, 0).Select
Loop
Application.ScreenUpdating = True
MsgBox "Done!"
End Sub