The Huawei E800 info available from Huawei is not helpful if you are using Ubuntu 7.10! A post from Ubuntu Forums for the Huawei E220/620 had some info re wvdial, using the wvdial.conf suggested and modprobing the device, I could get it to start, but the connection kept dropping out. Perhaps Hardy Heron will support this device (it’s a Vodafone unit, works well in XP SP2)
I suupose it is a bit unreasonable to expect Ubuntu to support every device ‘out of the box’, but the ISPs/Telco’s could help by offering drivers for other OS than just Windows…