I had a lot of trouble finding this information so I'll post it here for anyone who had the same trouble getting Medianet to work with your Audiovox 4100 phone. Cingular tech support was no help.

Click Connection Settings

Edit settings for connection.

Enter a name. I used "Cingular"

Select a modem.
Cellular Line (GPRS)

Next

Access Point
wap.cingular

next

user name WAP@CINGULARGPRS.COM
PASSOWRD CINGULAR1

FINISH

EDIT PROXY

CHECK BOTH BOXES
THIS NETWORK CONNECTS TO THE INTERNET
THIS NETWORK USES A PROXY

ADVANCED

wireless.cingular.com port 80
wap 66.209.11.61 port 9201
secure wap 66.209.11.61 port 9203
socks localhost port 1080
type socks 4

ok unitl you hit the today screen.

go to internet explorer and type http://device.home

You should connect.ap