Another $.02
Code:
Function FormatDMS(ByVal Degs As Double) As String
 Dim Sign As Long
 Sign = Sgn(Degs)
 Degs = Int(Abs(Degs) * 3600 + 0.5) / 3600 '-- rounding to second
 FormatDMS = Sign * (Int(Degs)) Mod 360 & Format(Degs / 24, "°nn'ss\""")
End Function