I would say get a good patent lawyer and patent it first, but that might be more trouble than its worth: http://www.startupsmart.com.au/intellectual-property/patent-attorneys-under-fire-over-crippling-fees/201201175095.html

Anyway, is it something that you can make at home? Depending on what it is, it might be worth trying to make some as just a weekend hobby, take them to craft markets, and see how they do.