Advocating your favourite software or distro to other open source users is good, but what about the real challenge of getting those who only know 'The Dark Side' to experience freedom?
There are plenty of programs, apart from the obvious OpenOffice.org and Mozilla choices, that are available cross-platform, affording plenty of opportunity to give your Windows-using colleagues the chance to experience the quality of open source (not just closed source freeware).
All users of open source products are testers (the same is true for paid software, they just don't admit it) and you don't have to be experienced to help.
To the expert, anything is easy, it often takes the inexperienced user, or complete newbie, to point out the unintuitive way some programs perform some tasks. If you think things could be done better, say so.
It is often said that programmers start a project to scratch their own itch, but users have itches too. If a program doesn't do quite what you want, file a feature request on its bug tracker or discuss it on the forums?
You will probably find others want something similar and might gain enough support to motivate someone to code the feature. Even if you don't program yourself, you can still help this way. Just remember, though, this is a request and you have no right to expect any feature you do not code yourself.
"I like positive criticism" is as big a lie as "the cheque is in the post", but constructive criticism does help. If you think something could be better handled, say so, but in a way that helps to improve it.
"X sucks" will get you ignored, "X would work better if done like this because..." may get you thanks, and a better program.
If patching to fix a bug doesn't satisfy your need to contribute, how about extending the software by adding a feature, either to the core code or as a plugin?
One of the benefits of open source is that it encourages good coding style, as plenty of people will see it, making it easier for others, or you, to jump in.
Let's be honest, we've all felt quietly smug hearing Windows users discussing the price of software or their concerns about malware.
Do your friends a favour and be openly smug. Let them know that you are not only unconcerned about these things but that you generally don't even think about them. Show them that one of the greatest freedoms of open source is freedom from fear.
A default setup is the state that exists between installation and the user finding the preferences editor.
Would Ubuntu really have survived so many years of brown were it not so easy to change? Do you have a goodlooking desktop? Then why not share it on gnome/kde/xfce-look.org?
18. Be nice
Never forget that most open source programmers do it for little or no financial rewards, and none from you (unless you choose to donate). So be polite, whether it is asking for features or reporting bugs, and remember to demand only those rights that were included in the purchase price.
19. Just do it
It doesn't have to be big, but do something now. Prevarication is easy – although some of us work hard at it – but where would we be if all those open source developers waited until tomorrow to scratch their itch?
The first step doesn't have to be big, earth-shattering or even particularly helpful, the important thing is to get involved, then take it from there.