Smile.Amazon.com is a parallel site Amazon has that allows you to pick a charity that they'll donate a bit of your purchase to. USHPA is now a listed charity there.
Amazon says they donate a portion that they would have otherwise spent on advertising.
You just do your ordering from smile.amazon.com instead of from amazon.com, each time. Specify your charity is:
"United States Hang Gliding and Paragliding Association Inc"
I just changed my Amazon account to AmazonSmile and I encourage everyone else who shops there does the same. I buy lots of stuff there and look forward to seeing some of that dough go to SHGA!