Digital Photography
You can get an inexpensive digital camera for $100 or less and see if you like photography. If you find you really like it, you can get a camera with a pretty decent lens for $300 and up. If you have a computer or other device to save them on It doesn't cost anything after that.
Get An Instrument. Your Neighbors Will Love It. :-)
Or, Volunteer Somewhere If You're Able.
Great ideas Dale, I love that top pic, there's so many wonderful hobbies to choose from!