Stream Audio Live?

Friend of mine asked me about something, I really don't find anything with a quick search.

Basically I need something that can take an audio feed from a computer, and stream it to listeners. This will only be a once a month thing. It's got to be live (not going to be pre-recorded).

Now, the computer is probably going to be mobile, so it might only sit on a 2G Cellular network. So, I can't just have everyone connecting to that computer. All that computer needs to do is stream it to a server, which can then relay it out to folks online.

What kind of service offers something like this? Free is preferred but cheap is OK too. Again, only used about once a month.

You could set up Debian/Ubuntu on a spare box or virtual machine, and install Icecast2 on it. Icecast configuration consists of changing the stream source/admin passwords from 'hackme' to something else, in the config .xml file. For streaming to the Icecast server, you can use VLC. Just make sure you open the ports to it in your router.