I find this useful:
Dim st As System.IO.Stream
Dim sr As System.IO.StreamReader
Dim req As System.Net.WebRequest = System.Net.WebRequest.Create("http://www.whatismyip.com/automation/n09230945.asp")
Dim resp As System.Net.WebResponse = req.GetResponse
st = resp.GetResponseStream
sr = New System.IO.StreamReader(st)
GetLocalIPAddress = sr.ReadLine.ToString