NetworkManager & VMC - easy as pie
Work gave me a 3G dongle. It's a Huawei E270.
I was a little concerned with support for this under Linux. However, the Vodafone guys over at https://forge.betavine.net/projects/vodafonemobilec/ make a driver for the Huawei modems (the Vodafone dongles use the Huawei chipsets).
Installation was simple. See the site for details.
Better yet, upon inserting the dongle I noticed that NetworkManager picked it up and asked me to configure it using a wizard. The wizard was great, I just selected my provider and what type of contract I had. After that I could click the NetworkManager applet icon and select "Vodafone Mobile Contract". Works a treat.
Very pleased, occasionally some really nice usability features pop out at me. This was one of them.