Hardware 

Nothing to see here - move along. The drivers (nozomi) are already included in Ubuntu 7.10. No need to install anything. 

Software 

Install gcom and wvdial:

> sudo apt-get install gcom wvdial

Configuration

 Create a new /etc/wvdial.conf (backup the old one)

---SNIP---

Dialer Defaults]
baud = 57600
Modem = /dev/noz0
Dial Command = ATD
Carrier Check = no

[Dialer Orange]
Init = AT+CGDCONT=1,"IP","mobileoffice3g","",0,0
Phone = *99***1#
Username = orange
Password = internet

[Dialer Setup]
init = AT+CFUN=1

[Dialer Status]
init1 = AT+COPS?;+CSQ

---SNIP--- 

Connect

> gcom -d /dev/noz0

Enter PIN number: ****
Waiting for Registration..(120 sec max)...
Registered on Home network: "Orange CH",2
Signal Quality: 0,99
 

>  wvdial Orange

WvDial<*1>: WvDial: Internet dialer version 1.56
WvModem<*1>: Cannot get information for serial port.
WvDial<*1>: Initializing modem.
WvDial<*1>: Sending: AT+CGDCONT=1,"IP","mobileoffice3g","",0,0
WvDial Modem<*1>: AT+CGDCONT=1,"IP","mobileoffice3g","",0,0
WvDial Modem<*1>: OK
WvDial<*1>: Modem initialized.
WvDial<*1>: Sending: ATD*99***1#
WvDial<*1>: Waiting for carrier.
WvDial Modem<*1>: ATD*99***1#
WvDial Modem<*1>: CONNECT 393600
WvDial<*1>: Carrier detected.  Waiting for prompt.
WvDial<Notice>: Don't know what to do!  Starting pppd and hoping for the best.
WvDial<Notice>: Starting pppd at Tue Mar 25 11:53:03 2008
WvDial<Notice>: Pid of pppd: 8694
WvDial<*1>: pppd: [13]+
WvDial<*1>: Using interface ppp0
WvDial<*1>: pppd: [13]+
[...]
WvDial<*1>: Authentication (CHAP) started
[...]
WvDial<*1>: Authentication (CHAP) successful
[...]
WvDial<*1>: local  IP address 10.23.1.55
WvDial<*1>: pppd: [13]+
WvDial<*1>: remote IP address 10.64.64.64
WvDial<*1>: pppd: [13]+
WvDial<*1>: primary   DNS address 213.55.128.1
WvDial<*1>: pppd: [13]+
WvDial<*1>: secondary DNS address 213.55.128.2
WvDial<*1>: pppd: [13]+
WvDial<*1>: pppd: [13]+
WvDial<*1>: Script /etc/ppp/ip-up run successful
WvDial<*1>: Default route Ok.
WvDial<*1>: Nameserver (DNS) Ok.
WvDial<*1>: Connected... Press Ctrl-C to disconnect
WvDial<*1>: pppd: [13]+

References:

http://circle.ch/blog/c28.html