I have an idea for image copy-protection that I'm in the process of coding up and plan on selling to one of my clients who sells images online. If successful I think there would be a lot of people in a similar situation to my client who would be interested in the code also. I think this is a fairly unique idea that could be packaged into a saleable product - but if I did do this, I wouldn't want some big corporation decending on me with their lawyers after all my hard work. So before I put too much work into this I'd really like to know how I'd go about finding if this idea has been patented already and whether I'd get in trouble if I sold my product and if it would be worthwhile patenting the idea myself. Although I find the idea of software patenting abhorrent, it would be more to protect myself from the usual suspects than to stop fellow-developers from using the idea (if it is in fact a worthwhile one).

I live in Australia, so an idea of who to go and see and a ball park figure of how much money I'd be looking at having to pay would be fantastic (in orders of a magnitude: 100s, 1000s, 10s of thousands of dollars, etc).

Cheers

Iain