The patent process requires some patent fee. Does anybody know of an open alternative? If not patent, atleast something that can prove that the idea was originated by somebody on some particular date and time.
Get your idea down on paper, seal it, and mail it to yourself. This will of course prevent no one from infringing on your idea, but if all you are looking to do is prove someone came up with something before a certain date, this should do the job. Also, IANAL, so I don't know exactly what legal uses this would have.
The Writer's Guild of America offers a registration service for written works. See <a href="http://www.wgawregistry.org/webrss/" rel="nofollow">http://www.wgawregistry.org/webrss/</a>. It's ostensibly for screenplays, but they don't actually check the content of what is being registered. There is a modest fee. And whether or not registering with them will ever produce any actual benefit is IMHO highly questionable. But YMMV and all that.
If you just want to prove that you had "idea X" at any given point in time, the simplest thing I can think of is to document the idea and then have the document notarized. Since a notary is a legally accepted witness to a signature, this should hold up. It may even be enough to mount a challenge against a subsequent patent (insert obligatory IANAL).<p>But if you really want to have a hope of preventing someone else from patenting it, then you need to publish.
A provisional patent is cheap, and if you just want to defend yourself from someone else later patenting your idea, it works just fine. You just write up a nice human-readable description of what you're doing and submit it to the USPTO. I think it's like a hundred bucks or so. Filing a full patent costs about $500. If you're willing to work, meaning, read a couple of books, read a couple of patents front to back, it's not <i>that</i> hard to file your own (called "Pro Se" by patent folks). Once you learn the ins and outs of patents, it's really not that hard nor that expensive to patent something yourself. At the very least, if you do file your own, you get "patent pending" protection ("protection" meaning, you've legally allowed to warn potential infringers that you've filed the papers officially) for a good 3-5 years while the patent office reviews your application.