Thanks for the response.
I thought that changing to "client.connect(gserver, 81)" would make my Arduino use its own port 81 for that communication. Thanks for clarifying.
The first serial messages that I get are:
Attempting to connect to SSID: belkin.3c2
Connected to wifi
SSID: belkin.3c2
IP Address: 192.xxx.2.27
except digits in place of 'x's - I just don't want to put the whole ip address up on the web. I can successfully go to this ip address in my browser and retrieve the "Hello" greeting from my arduino when the setup()'s WiFiClient code is commented out.
As another update, there's a current thread where someone is trying to do the same thing using the Ethernet shield at (http://arduino.cc/forum/index.php/topic,126545.0.html). And a good response is at (http://arduino.cc/forum/index.php/topic,80137.15.html). I'm not sure what all the relevant differences are between doing it with Ethernet and WiFi, though. One point that was brought up in that thread is that "client.stop()" can fail if there is data in the receive buffer, so that might be related to my problem.