Hi Jeff,
Assume these are for text and not numbers.
SpecialCells is an automatic limitation to the used range,
in addition limited to text constants in the following.
(untested code)
Sub Jeff_space()
Application.ScreenUpdating = False
Application.Calculation = xlCalculationManual
Dim Cell as Range
On Error Resume Next 'In case no cells in selection
For Each Cell In Intersect(Selection, _
Selection.SpecialCells(xlConstants, xlTextValues))
if length(cell.value) > 0 then
cell.value = left(cell.value,length(cell.value)) & " " & right(cell.value)
end if
Next
Application.Calculation = xlCalculationAutomatic
Application.ScreenUpdating = True
End Sub
More information on the extra coding in
http://www.mvps.org/dmcritchie/excel/proper.htm