call DIALOG call center and ask for GPRS settings. They'll send you the settings by a SMS. save it. restart the phone. that's it. manual configuration is bit difficult coz settings depends on ur mobile model.
if you wanna use the phone as a modem, connect the phone to the PC.it'll detect as a modem if you have install the phone drivers. Then create a new internet connection using the phone modem. provide the dialing number as #99*#. you are connected to the net...