1. If you want to check if the PDA has network connectivity:

public static bool HasNetworkConnectivity()
       // Call this class as follows:  bool bResponse =
Net.IsWebAccessible;
       {
           HttpWebRequest hwrRequest;
           HttpWebResponse hwrResponse;
           string strUrl = @"http://www.microsoft.com/";
           bool bConnected = false;
           try
           {
               hwrRequest = (HttpWebRequest)WebRequest.Create(strUrl);
               hwrResponse =
(HttpWebResponse)hwrRequest.GetResponse();
               if (hwrResponse.StatusCode == HttpStatusCode.OK)
               {
                   bConnected = true;
               }
               hwrResponse.GetResponseStream().Close();
           }
           catch (WebException we)
           {
               bConnected = false;
           }
           catch (Exception ex)
           {
               bConnected = false;
           }
           finally
           {
               hwrRequest = null;
               hwrResponse = null;
           }
           return bConnected;
       }

Take also a look at ConnectionManager from OpenNETCF. I think it gives
you the ability to enumerate all connections of the device. If you need
that, tell me so that I can show you some code.

Hope it helps.

Regards.