Legal question: "idea" patent/copyright

Every once in a while I get an idea for an invention.
It usually starts with "I wish they'd make a...."
Some of my ideas were good enough that the product eventually came out. Eventually...somebody else thought of it too.

I'm not an engineer, and don't have the cash or expertise to get a product up and running. I'd just like to cash in on this (OK "the easy way") by making the suggestion to an established manufacturer.

Right now I have an idea for a modification to an eletronic entertainment device that I think somebody like Sony might be interested in.

Here's my question: If I write the idea down, and mail it to myself first, and don't open the envelope, I'd have proof that it was my idea. Or would I? Would it stand up in court? Would it be better to hire an attorney and mail it to him? What if I mailed it to several trustworthy friends who could later testify in my behalf?

I really don't want to get into trying for a U.S. patent, etc.

I'd appreciate any light our legal experts could shine on this.
And I'll cut you in if it works.
Thanks.

there is no easy way.

I am not a lawyer; I am an artist who has done patent drawings. You cannot copyright an idea. You need a lawyer/agent to present your patented inventions to companies, however having a patent(s) and a lawyer will not insure you.

Case in point, my friend the lawyer who has 4 patents on a very unique thing, took all the steps required to protect himself and still had a terrible fight on his hands over his invention. The invention was so huge there was no way to make a prototype, so by the time he had 2 patents he had an animated film made of his invention, which was distributed to the interested companies. There were no takers - but a year later a famous company he'd talked to unveiled his invention to the world as their own. The company did interviews on national television explaining how they'd arrived at such a great idea. The invention was extremely popular, touted now, 4 years later, as the best and most exciting of its kind.

My friend sued the company, having by then 4 patents on the invention, and after years in court and very expensive atty. fees, my friend has a small victory but not much in the way of a settlement. I would imagine that the invention has brought millions and millions of dollars to the company that stole it, none of which my friend will see.

I've had quite a bit of experience with copyrights, and a couple relatives and friends have obtained some patents -- or gone broke trying.

1. You can't copyright an idea. Period. The mailing it to yourself used to be touted as a way to protect written material (books, stories, plays, etc.), but even that only takes you through common law copyright, which isn't the same as registered copyright.

2. My understanding of patents, based on what my family members did, is that you have to have a working model of the contraption to prove that it does what you say it can do. It also has to be unique enough not to be just a modification of a common object. A friend and her husband spent thou$and$ trying to get a patent on what they thought was a "unique" type of luggage for pets. After several patent applications and then a change of lawyer, they discovered they couldn't get a patent on what was essentially just a rearrangement of pockets on a standard duffel bag; they ended up trademarking just their product name, and wished they had had better legal advice at the beginning!

If your idea is something electronic, why not find a friend who can help you actually develop it, and then share the patent?