Scott,
Have you searched the US patent database?
Have you tried google scholar?
My experience is that if it is a good idea - someone already had it. Only if it is very specific to a certain field is there usually something left to invent.
Generally, if you have to do a patent application, it will run >5k. That's just to have a patent in the US. That will not protect your idea world wide. Also, by filing for a patent, your patent will eventually become public and everyone can see it. It is easily ripped off by anyone. Even if someone blatantly takes your idea and runs with it - how are you going to defend your patent? Your legal department?
Be weary of companies advertising looking for "inventors". If you get serious about getting a patent, go through professional references - find someone that works with an office. It doesn't take much to put together a patent that the patent office will accept, but that doesn't mean it will hold up in court when you need to defend it.
And often a patent isn't even defendable, because with a few tricks the people that rip you off build a similar idea based on yours. They may have never had the similar idea without reading your patent. but that will still be okay.
I know people that have invented things and tried to sell their IP to large companies. In every cfase I know the large company said "thanks but we have our own R&D group" - not interested.
In summary, I would not worry about filing a patent. If you need outside help from any business, file a non disclosure agreement with them. That will protect your idea. I.e. if you have a machineshop build you something or if you have a test lab measure something for your project. Once you know that you have something and you are getting close to selling it through Wayne, put in a basic patent application and stamp the part "patent pending" to discourage blatant copies.
Hope this helps?
George
PS: A lot of large companies keep "trade secrets". Coca Cola doesn't go out and patent their recipe - they keep it locked up instead. Would be too easy to use the recipe and change a couple of ingredients to call it something else.