I am an Arduino fan and I really love it! Because Arduino is so great and makes many complicated things much easier, I think I should try to support Arduino in ways I can. I know that buying official boards is a way to give back to Arduino, but in many cases Arduino derivative boards seems to be the better choice for me, regarding function and price. For example, there is one Arduino derivative board that has integrated XBee socket and Ethernet port. It costs less than official board plus shields, and is also more compact. But I guess the company that make these derivative boards hardly financially give back to Arduino. I feel kind of guilty about benefiting from Arduino but not giving back anything to it. So, are there other ways to support Arduino besides buying official boards?
I think you could always send donations to the founders of Arduino,
or buy the real Arduino's and give them to schools in your neighbourhood (would also be appreciated I guess)
or create a local Arduino community an other way?
You could write some librarys, something like that.
Be a"good and active" contributor to a Arduino oriented playground/forum.
Blog about Arduino.
Write a book.
Invent a world-beating anti-spam solution.
Write a book.
One dedicated to the MEGA and/or DUE as there are quite plenty about UNO
Be an active member to this board.
Even a starter can help out others by contributing and answering questions, or even asking questions.
Of course, nonsense and opinions brought as the absolute truth aren't much appreciated.