On Guard Fend off copycat competitors with these secret weapons.

March 1993 will forever live in infamy for me. That month, all my hard work in marketing the TopsyTail was eroded by boatloads (literally) of TopsyTail knockoffs entering the marketplace at a fraction of my sales price.

Thankfully, I was one of the lucky ones. I had taken my idea to market swiftly and sold large volumes before the "legal thieves" arrived with their knockoffs. Most entrepreneurs, unfortunately, are not as lucky. All too often they see their ideas brought to market by someone else--someone who reaps all the benefits and profits. Their only recourse is a very expensive (about $250,000) and risky two-year court battle--which is an option only if they protected their idea with a patent. And did I mention that the odds of winning aren't all that great? Slightly more than 60 percent of patent holders win their lawsuits.

The good news is there are ways to protect your idea. The key is to be proactive and move quickly to discourage others from copying your products. Following are four of the best weapons to protect you.