If I've got you right, perhaps this will help?
http://www.officearticles.com/excel/fill_in_the_blanks_in_microsoft_excel.htm
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Hope it helps!
Anne Troy
www.OfficeArticles.com

You could use a macro:

Option Explicit
Sub testme()
   Dim myCol1 As Range
   Dim myCol2 As Range
   Dim myCell1 As Range
   Dim myCell2 As Range
   Dim wks As Worksheet
   Dim newWks As Worksheet
   Dim oRow As Long
   
   Set wks = Worksheets("Sheet1")
   
   With wks
       Set myCol1 = .Range("a1", .Cells(.Rows.Count, "A").End(xlUp))
       Set myCol2 = .Range("b1", .Cells(.Rows.Count, "B").End(xlUp))
       If myCol1.Cells.Count * myCol2.Cells.Count > .Rows.Count Then
           MsgBox "Too much data!"
           Exit Sub
       End If
   End With
   
   Set newWks = Worksheets.Add
   
   oRow = 0
   For Each myCell1 In myCol1.Cells
       For Each myCell2 In myCol2.Cells
           oRow = oRow + 1
           With newWks.Cells(oRow, "A")
               .Value = myCell1.Value
               .Offset(0, 1).Value = myCell2.Value
           End With
       Next myCell2
   Next myCell1
   
End Sub

If you're new to macros, you may want to read David McRitchie's intro at:
http://www.mvps.org/dmcritchie/excel/getstarted.htm