This is directly taken from the VBA Macros CD available on this website (I do not take the credit). It will put the new data on the 2nd sheet.
<font face=Courier New><SPAN style="color:#00007F">Sub</SPAN> CopyingWithoutDoubled()
<SPAN style="color:#00007F">Dim</SPAN> wks <SPAN style="color:#00007F">As</SPAN> Worksheet
<SPAN style="color:#00007F">Dim</SPAN> rngFind <SPAN style="color:#00007F">As</SPAN> Range
<SPAN style="color:#00007F">Dim</SPAN> intRow <SPAN style="color:#00007F">As</SPAN> <SPAN style="color:#00007F">Integer</SPAN>, intCol <SPAN style="color:#00007F">As</SPAN> <SPAN style="color:#00007F">Integer</SPAN>, intRowT <SPAN style="color:#00007F">As</SPAN> <SPAN style="color:#00007F">Integer</SPAN>
<SPAN style="color:#00007F">Set</SPAN> wks = Worksheets("Sheet2")
intRow = 1
intCol = 1
wks.Columns("A").ClearContents
<SPAN style="color:#00007F">Do</SPAN> <SPAN style="color:#00007F">Until</SPAN> IsEmpty(Cells(intRow, intCol))
<SPAN style="color:#00007F">Do</SPAN> <SPAN style="color:#00007F">Until</SPAN> IsEmpty(Cells(intRow, intCol))
<SPAN style="color:#00007F">Set</SPAN> rngFind = wks.Columns(1).Find(Cells(intRow, intCol), _
lookat:=xlWhole, LookIn:=xlValues)
<SPAN style="color:#00007F">If</SPAN> rngFind <SPAN style="color:#00007F">Is</SPAN> <SPAN style="color:#00007F">Nothing</SPAN> <SPAN style="color:#00007F">Then</SPAN>
intRowT = intRowT + 1
wks.Cells(intRowT, 1).Value = Cells(intRow, intCol).Value
<SPAN style="color:#00007F">End</SPAN> <SPAN style="color:#00007F">If</SPAN>
intCol = intCol + 1
<SPAN style="color:#00007F">Loop</SPAN>
intRow = intRow + 1
intCol = 1
<SPAN style="color:#00007F">Loop</SPAN>
<SPAN style="color:#00007F">End</SPAN> <SPAN style="color:#00007F">Sub</SPAN></FONT>