This puts the output in a new column on a new worksheet:
Option Explicit
Sub testme01()
Dim wks As Worksheet
Dim RptWks As Worksheet
Dim iRow As Long
Dim oRow As Long
Set wks = Worksheets("Sheet1")
Set RptWks = Worksheets.Add
With wks
RptWks.Cells(1, "A").Value = .Cells(1, "A").Value
RptWks.Cells(2, "A").Value = .Cells(1, "B").Value
oRow = 2
For iRow = 2 To .Cells(.Rows.Count, "A").End(xlUp).Row
If .Cells(iRow, "A").Value <> .Cells(iRow - 1, "A").Value Then
'add the group indicator
oRow = oRow + 1
RptWks.Cells(oRow, "A").Value = .Cells(iRow, "A")
End If
oRow = oRow + 1
RptWks.Cells(oRow, "A").Value = .Cells(iRow, "B").Value
Next iRow
End With
End Sub
If you're new to macros:
Debra Dalgleish has some notes how to implement macros here:
http://www.contextures.com/xlvba01.html
David McRitchie has an intro to macros:
http://www.mvps.org/dmcritchie/excel/getstarted.htm
Ron de Bruin's intro to macros:
http://www.rondebruin.nl/code.htm
(General, Regular and Standard modules all describe the same thing.)