Confirm that your device is detected using the command given below.
{codecitation}
tail -f /var/log/messages
{/codecitation}

Now you should see something like:
{codecitation}
usb 4-1: configuration #1 chosen from 1 choice
usbserial_generic 4-1:1.0: generic converter detected
usb 4-1: generic converter now attached to ttyUSB0
{/codecitation}
Now, your system can identify the new USB device which you have inserted and you can confirm this by running lsusb command.
{codecitation}
———————————————–
# lsusb
Bus 005 Device 004: ID 046d:08c6 Logitech, Inc.
Bus 005 Device 001: ID 0000:0000
Bus 004 Device 027: ID 05c6:6000 Qualcomm, Inc.
Bus 004 Device 001: ID 0000:0000
———————————————–
{/codecitation}

Now create the dialup profile. Its can be created with “wvdialconf” command.

Open the /etc/wvdial.conf file and edit it according to your need. Give your phone number, username and password.
{codecitation}
more /etc/wvdial.conf
[Dialer Defaults]
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Init3 AT+CRM=1;CPS=33;+CMUX=1;CTA=0
Modem Type = Analog Modem
ISDN = 0
Phone = #777
Modem = /dev/ttyUSB0
Username = xxxxxxxxx
Password = xxxx
Baud = 460800
Stupid Mode = 1
Auto DNS
Check Def Route
{/codecitation} 

Now give “wvdial” command to connect. To disconnect, press ctrl + c.

Surf web & enjooaaay.

I have tested it in Fedora 11 and in Ubunutu 9