I do not have developers skills myself and that means there is nothing that I can contribute in the technical aspects of Bitcoin but what I do is to help spread the news about Bitcoin to people. I use any opportunity that I get to spread the word and I think that is what most of us can do to help contributing to the growth of Bitcoin. The more people that know about Bitcoin, the more people that will invest and starts to adopt Bitcoin. From there we can get more shops accepting Bitcoin payment and this will help in our request for the currency to be approved by the government so more people can adopt it's usages. You can contribute to the price appreciating by buying more Bitcoin and taking some supply out of circulation to help increase the price.