But start small.

The things I've tried so far:

1) Re-selling magazines on eBay
2) Placing a few candy machines in businesses
3) Investing in stocks
4) Buying a large-format printer with a friend to sell large prints
5) Online ventures (traffic generation sites)
6) Loaning a friend money for a real-estate flipper

I haven't made a lot of money at any of these at the moment, but I've never put in more than I could afford to lose, and I haven't quit my day job (yet). It's a lot easier to try new things if you budget for them and know that you won't depend on the success of the venture to eat and clothe yourself. If it ends up doing that, great; otherwise, you can always learn from the experience.