Hooray! My Sierra Wireless AirCard 880 is working with Ubuntu 8.04.1 (Hardy Heron)! This is something I have been wanting to get working for quite a while. What it means is that I won't have to boot Vista in order to use my laptop on the train and bus during my daily commute.
There were two keys to getting it to work. First, I needed some specific information that you can only get from your cellular service provider - in my case, Swisscom (I purchased my card as an OEM product sold as the Swisscom Mobile Unlimited Card). What you need to get from them is the APN address, and a Login and Password. In fact with Swisscom the User and Password information are actually not necessary, but the Ubuntu card configuration requires them.
Second, I had to remove the PIN code from the card, as I was not able to get it working with PIN, and when I asked for help again they suggested simply removing it (Duh!).
I was then able to configure the card to work with the wvdial utility, by entering the data in the /etc/wvdial.conf file, and then running "sudo wvdial", which dials and connects the card and starts pppd. There is a tiny glitch in the dialing, because wvdial really wants to give a login and password, but it times out waiting for the prompt and says something like "no login prompt, proceeding without it, hope this works...".
Now, this is clearly not an optimal way to configure and use this card, because it requires manual editing of the config file and manual execution of the program, but it's way better than nothing! I have tried to configure it through the Ubuntu 8.04 network manager, as a "Point to Point Connection", and couldn't get it to work. I have also tried it on Ubuntu 8.10 alpha5 as a "Mobile Broadband" connection, and although I seem to get pretty close, I have not yet been able to get it to connect. I will, of course, continue trying to get this working.
I am so pleased with this! Hooray!