Many 3G USB modems have 2 different operating modes. By default they appear as a memory stick. The memory stick contains a driver, usually for windows only. This way no additional SW has to be delivered or installed. The driver would start automatically and switch the USB stick into modem mode. Now, depending on the driver and stick, the 3G radio might be used as modem, for SMS and potentially for voice over 3G.
Ubuntu 10,4 is able to handle 3G USB modems, but can not switch between the modes. Ubuntu sees just a memory stick.
Sakis3G has published a script which support switching to the modem mode and can even establish the 3G data link. Switching to modem mode is actually enough, as Ubuntu is able to recognize the modem and setup the connection.
Huawei's E1750 HSPA USB Stick as sold by ToT3G in Thailand:
lsusb printout after plugging in (memory stick mode)
Bus 001 Device 011: ID 12d1:1446 Huawei Technologies Co., Ltd.
lsusb printout after swicthing into modem mode (Ubuntu can handle the modem then)
Bus 001 Device 010: ID 12d1:1001 Huawei Technologies Co., Ltd. E620 USB Modem
The script can be downloaded directly from sakis:
Unzip, add execution rights and start:
$ gunzip sakis3g.gz
$ chmod a+x sakis3g
$ sudo ./sakis3g
If the network and APN is know by the script, a simple click on "connect to 3G" is enough to establish the data connection. The script can also show the sent and received data volume.