loSock = CREATEOBJECT('MSWinsock.Winsock.1')
? loSock.LocalIP
loSock = .NULL.

*-- Option 1 (With VFP 9 Sedna)

? IpInternet()

FUNCTION IpInternet()
  LOCAL My AS My
  My = NEWOBJECT("My","My.vcx")
  ERASE "IP.txt"
  IF 0 = My.Computer.Network.DownloadFile("http://ip1.dynupdate.no-ip.com/", "IP.txt")
    RETURN FILETOSTR("IP.txt")
  ELSE
    RETURN ""
  ENDIF
ENDPROC

*-- Option 2: With Windows API

? IpInternet()

FUNCTION IpInternet()
  DECLARE LONG URLDownloadToFile IN URLMON.DLL ;
    LONG, STRING, STRING, LONG, LONG
  ERASE "IP.txt"
  IF 0 = URLDownloadToFile(0, "http://ip1.dynupdate.no-ip.com/", "IP.txt", 0, 0)
    RETURN FILETOSTR("IP.txt")
  ELSE
    RETURN ""
  ENDIF
ENDPROC

*-- Option 3: With VFPConnection.FLL by Craig Boyd (Download http://www.sweetpotatosoftware.com/files/vfpconnection.zip)

? IpInternet()

FUNCTION IpInternet()
  SET LIBRARY TO (LOCFILE("vfpconnection.fll","FLL")) ADDITIVE
  lcIP = HTTPToStr("http://ip1.dynupdate.no-ip.com/")
  RELEASE LIBRARY "vfpconnection.fll"
  RETURN lcIP
ENDPROC