As of February 1, 2007, the United States Patent and Trademark Office will no longer be offering the $10 document disclosure program. Given the benefit (or lack thereof) the program offers inventors, it appears the program was actually significantly overpriced. Just like the old wives tale of protecting your invention by sending yourself a letter with the invention disclosed therein, the document disclosure program apparently gave some inventors a false sense of security that the document disclosure program afforded them something more than a conception date. According to the Patent Office, some inventors erroneously believed the document disclosure program was the equivalent of filing a patent. Finding that the document disclosure program provides little in any benefit to inventors, the Patent Office has discontinued the program.
If your only concern is obtaining a date of conception, a provisional patent application will provide the same protection. If you are actually interested in protecting your invention though, a regular patent is still, by far, the best option.