Evan: Select the range you're counting before you run the macro.

Sub MyCounter()
OneCounter = 0
For Each c In Selection
If c.Value = 0 Then
c.Offset(0, 1).Value = 0
OneCounter = 0
Else
OneCounter = OneCounter + 1
If c.Offset(1, 0).Value = 0 Then
c.Offset(0, 1) = OneCounter
Else
c.Offset(0, 1) = 0
End If
End If
Next c
End Sub

[Tested OK]

Select the range you're counting before you run the macro.