Dear readers,
This is a post just in case anyone has difficulty in configuring the USB modem Huwaei 1260. My service provider is Tataindicom from in India.
I'm using photon plus broadband connection. Here's how I configured it.

Login as root.
Insert the modem in a USB port.
Do a lsusb command.
You will get the vendor id and the product id.
[root@localhost ~]# lsusb
Bus 003 Device 001: ID 0000:0000
Bus 002 Device 001: ID 0000:0000
Bus 001 Device 001: ID 0000:0000
Bus 005 Device 002: ID 15d9:0a37 Unknown Mouse
Bus 005 Device 001: ID 0000:0000
Bus 004 Device 002: ID 12d1:140b Huawei Technologies Co., Ltd.
Bus 004 Device 001: ID 0000:0000

Here the vendor id is 12d1 and the product id is 140b.
Now you have to do a modprobe.

[root@localhost ~]# modprobe -r usb-storage usbserial
[root@localhost ~]# modprobe usbserial vendor=0x12d1 product=0x140b

Run wvdialconf as below.

[root@localhost ~]# wvdialconf /etc/wvdial.conf
Scanning your serial ports for a modem.

ttyS0<*1>: ATQ0 V1 E1 -- failed with 2400 baud, next try: 9600 baud
ttyS0<*1>: ATQ0 V1 E1 -- failed with 9600 baud, next try: 115200 baud
ttyS0<*1>: ATQ0 V1 E1 -- and failed too at 115200, giving up.
Port Scan<*1>: S1 S2 S3
WvModem<*1>: Cannot get information for serial port.
ttyUSB0<*1>: ATQ0 V1 E1 -- OK
ttyUSB0<*1>: ATQ0 V1 E1 Z -- OK
ttyUSB0<*1>: ATQ0 V1 E1 S0=0 -- OK
ttyUSB0<*1>: ATQ0 V1 E1 S0=0 &C1 -- OK
ttyUSB0<*1>: ATQ0 V1 E1 S0=0 &C1 &D2 -- OK
ttyUSB0<*1>: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0 -- OK
ttyUSB0<*1>: Modem Identifier: ATI -- Manufacturer: +GMI: HUAWEI TECHNOLOGIES CO., LTD
ttyUSB0<*1>: Speed 4800: AT -- OK
ttyUSB0<*1>: Speed 9600: AT -- OK
ttyUSB0<*1>: Speed 19200: AT -- OK
ttyUSB0<*1>: Speed 38400: AT -- OK
ttyUSB0<*1>: Speed 57600: AT -- OK
ttyUSB0<*1>: Speed 115200: AT -- OK
ttyUSB0<*1>: Speed 230400: AT -- OK
ttyUSB0<*1>: Speed 460800: AT -- OK
ttyUSB0<*1>: Max speed is 460800; that should be safe.
ttyUSB0<*1>: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0 -- OK
WvModem<*1>: Cannot get information for serial port.
ttyUSB1<*1>: ATQ0 V1 E1 -- failed with 2400 baud, next try: 9600 baud
ttyUSB1<*1>: ATQ0 V1 E1 -- failed with 9600 baud, next try: 115200 baud
ttyUSB1<*1>: ATQ0 V1 E1 -- and failed too at 115200, giving up.
WvModem<*1>: Cannot get information for serial port.
ttyUSB2<*1>: ATQ0 V1 E1 -- OK
ttyUSB2<*1>: ATQ0 V1 E1 Z -- OK
ttyUSB2<*1>: ATQ0 V1 E1 S0=0 -- OK
ttyUSB2<*1>: ATQ0 V1 E1 S0=0 &C1 -- OK
ttyUSB2<*1>: ATQ0 V1 E1 S0=0 &C1 &D2 -- OK
ttyUSB2<*1>: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0 -- OK
ttyUSB2<*1>: Modem Identifier: ATI -- Manufacturer: +GMI: HUAWEI TECHNOLOGIES CO., LTD
ttyUSB2<*1>: Speed 4800: AT -- OK
ttyUSB2<*1>: Speed 9600: AT -- OK
ttyUSB2<*1>: Speed 19200: AT -- OK
ttyUSB2<*1>: Speed 38400: AT -- OK
ttyUSB2<*1>: Speed 57600: AT -- OK
ttyUSB2<*1>: Speed 115200: AT -- OK
ttyUSB2<*1>: Speed 230400: AT -- OK
ttyUSB2<*1>: Speed 460800: AT -- OK
ttyUSB2<*1>: Max speed is 460800; that should be safe.
ttyUSB2<*1>: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0 -- OK
WvModem<*1>: Cannot get information for serial port.
ttyUSB3<*1>: ATQ0 V1 E1 -- failed with 2400 baud, next try: 9600 baud
ttyUSB3<*1>: ATQ0 V1 E1 -- failed with 9600 baud, next try: 115200 baud
ttyUSB3<*1>: ATQ0 V1 E1 -- and failed too at 115200, giving up.

Found a modem on /dev/ttyUSB0.
Modem configuration written to /etc/wvdial.conf.
ttyUSB0<Info>: Speed 460800; init "ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0"
ttyUSB2<Info>: Speed 460800; init "ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0"

The modem configuration will be written in /etc/wvdial.conf as below.

[root@localhost ~]# cat /etc/wvdial.conf

[Dialer Defaults]
Modem = /dev/ttyUSB0
Baud = 460800
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
ISDN = 0
Modem Type = Analog Modem
; Phone = <Target Phone Number>
; Username = <Your Login Name>
; Password = <Your Password>

Make changes as below to the /etc/wvdial.conf

[Dialer Defaults]
Modem = /dev/ttyUSB0
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Stupid Mode = 1
Modem Type = Analog Modem
Phone = #777
ISDN = 0
Username = internet
Dial Command = ATDT
Password = internet
Baud = 9600

Run wvdial

[root@localhost ~]# wvdial
--> WvDial: Internet dialer version 1.54.0
--> Cannot get information for serial port.
--> Initializing modem.
--> Sending: ATZ
ATZ
OK
--> Sending: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
OK
--> Modem initialized.
--> Sending: ATDT#777
--> Waiting for carrier.
ATDT#777
CONNECT
--> Carrier detected. Starting PPP immediately.
--> Starting pppd at Wed Mar 3 11:57:05 2010
--> pid of pppd: 3544
--> Using interface ppp0
--> local IP address 115.117.193.65
--> remote IP address 172.29.243.161
--> primary DNS address 203.200.230.244
--> secondary DNS address 202.54.29.5

Wow You are on to the net.

If your browser gives problems loading the pages add the nameservers in /etc/resolv.conf as below.

[root@localhost ~]# cat /etc/resolv.conf
search localdomain
nameserver 203.200.230.244
nameserver 202.54.29.5

Then run the browser, there should not be any problems.

Are you not suppose to block USB storage device so kernel can recognize it automatically?

Here is package I used to provide Huawei USB modem from CentOS 5.1. I do not know if this is still needed:
http://oozie.fm.interia.pl/pro/huawei-e220/

Here is also interesting application for Huawei USB Modems.

Oh, yes. please correct title of this thread, you misspelled "Huawei".