I have been passionate about science for many years now. Stemming from this passion is my desire to be involved in active science, and spread the amazing world science reveals. While donations can always be used help to spread good critical thinking, there are many things you can do even if you are strapped for cash.
1. Talk about it
It may not seem like much, but one of the best things you can do is just to share your passion with friends and family. If you see a science story that catches your eye, tell people about it. People are generally interested in science to varying degrees, so share what you know. The more people are talking about science, the more it will be a part of the public conciseness.
2. Join a Citizen Science Project
There are lots of projects out there where all the scientists need is a little of your time and help. A perfect example of this is the Galaxy Zoo project which I have mentioned several times before. Because of their success they have now expanded into Zooniverse. This includes 4 research projects you can help with watching everything form supernova to our own sun. You could also help with the mystery of the star Epsilon Aurigae with Citizen Sky. These are just a few examples from my own field of interest, but you can find projects across many other disciplines with just a little looking.
3. Volunteer at a Local Science Museum
This is a really fun way to spread excitement about science. There is nothing better than showing a child a simple demonstration and having their eyes light up. This is also a great way to meet other people who share your interest. As you teach people about science, you will probably find your own knowledge of science growing. Teaching any subject is a great way to solidify, and expand, on your own understanding.
These are by no means the true end to the list, but I want to keep it short for now. Maybe I will expand on this list in the future. In the meantime, feel welcome to put anything you have done to support science in the comments below.