One of the often overlooked support mechanisms for Open Source GIS applications is Internet Relay chat, better known as IRC. Many OS GIS projects maintain an IRC presence. Often times you will find the project developers hanging out on the channel and willing to answer questions (more about that in a bit). Speaking personally, the Quantum GIS project has used IRC for project coordination, communication, and user support for several years.
The IRC network of choice for many projects is Freenode. Quoting from their website:
Freenode provides discussion facilities for the Free and Open Source Software communities, for not-for-profit organizations and for related communities and organizations.
A quick survey of Freenode found channels for the following Open Source GIS projects:
I'm sure there are others in addition to those I've listed above. Aside from GIS projects, Freenode also hosts a massive number of channels related to Open Source, including applications, Linux distributions, languages, and organizations.
When joining a channel you should listen for a while to get a feel for the channels culture. Some channels are relatively quiet and orderly, while others can be quite turbulent. You will also find varying levels of tolerance for people that ask questions that have already been answered a dozen times in the documentation, mailing lists, and on the channels. I won't go into detail on IRC etiquette - there are plenty of websites available to provide an overview of the do's and dont's. I have found the GIS related channels to be quite friendly and helpful. Here are a few tips to aid you in getting started:
Listen, learn, and then speak. It pays to get a feel for the dynamics of the channel before jumping in.
Read the topic for the channel. It often contains important information, including how to ask a question.
Do your homework before you ask. As I stated before, asking questions that are plainly answered on the project's website or in the documentation can result in either no answer or a bit of friendly scolding.
Wait. Just because someone doesn't answer right away doesn't mean you are being ignored. People on IRC are usually busy doing something else at the same time they are on the channel. It may take a while for your question to be noticed. Be patient.
I really can't stress enough the need to use the available documentation and information before asking questions. The developers of OS software have spent a lot of time creating their wares and they have a reasonable expectation that you will expend some effort learning about the application. This shouldn't scare you off, just spend a little time preparing.
There are a lot of IRC clients available for Unix/Linux, OS X, and Windows. Search the web and find one that works for you. One of the easiest to get started with is Chatzilla which is readily available from mozilla.org. Other clients include Irssi (a personal favorite), X-Chat, KSirc, and Konversation. Once you have a client, connect to irc.freenode.net and then join the channel of interest. You'll have to do a bit of investigation to determine how to connect and join with your IRC client.
IRC can be a great resource when using Open Source GIS. Follow the tips above and you'll be on your way to becoming a good IRC citizen.