From the patent office FAQ: (this should help answer most if not all of Vapians questions)
1. What do the terms “patent pending” and “patent applied for” mean?
A. They are used by a manufacturer or seller of an article to inform the public that an application for patent on that article is on file in the United States Patent and Trademark Office. The law imposes a fine on those who use these terms falsely to deceive the public.
2. Is there any danger that the USPTO will give others information contained in my application while it is pending?
A. Most patent applications filed on or after November 29, 2000, will be published 18 months after the filing date of the application, or any earlier filing date relied upon under Title 35, United States Code. Otherwise, all patent applications are maintained in the strictest confidence until the patent is issued or the application is published. After the application has been published, however, a member of the public may request a copy of the application file. After the patent is issued, the Office file containing the application and all correspondence leading up to issuance of the patent is made available in the Files Information Unit for inspection by anyone, and copies of these files may be purchased from the Office.
From another area of the USPTO site:
Definition of term
The term “patent pending” can be applied toward various kinds of products awaiting the awarding of this kind of intellectual property protection, as is provided for in the legal and governmental system of the United States as one of the functions undertaken by the United States Patent and Trademark Office (USPTO). As such, the “patent pending” mark can be placed on a particular item claimed to constitute such an act of original invention, discovery or creation in order to provide notice to other potential users or claimants of patent rights that rights have been asserted before the USPTO, and might eventually be accorded.
Conditions affecting “patent pending” term
The USPTO administers a relatively demanding and quite lengthy process as must be undergone by an applicant before intellectual property protections can be accorded in this form, due to the restrictiveness of the rights accordingly granted to an inventor. On a case by case, “patent pending” cases have been recognized as potentially taking up to 3 years before the process can be fully concluded.
USPTO “investigation”
The period during which “patent pending” can be said to be in effect for the purported inventor of such a patentable, unique and useful product, process or idea will be largely taken up by the so-called process of “investigation,” as consists of the procedures administered by the USCIS toward the end of determining whether or not the submitted creation can be meaningfully, verifiably and reasonably be found to fulfill the various requirements for eligibility maintained by the agency.
Illegal “patent pending” claims
If a person places a patent pending mark on a product or invention, as well as any other potentially relevant item subject to intellectual property protections, he or she will be subject to legal actions, including in the form of prosecution, if this claim is found to have been asserted untruthfully and illegally. The determination that a patent pending claim was illegal is made in regard not to the eventual success or failure of supposedly patentable inventions gaining this kind of intellectual property protection right, but whether the claimant has taken the necessary step of at least applying for such rights. As such, a patent pending mark placed on an invention which has not in fact been submitted to the USPTO will thus raise the possibility of the wrongfully acting claimant being subject to various kinds of criminal and civil penalties. Wrongful patent pending claims are considered federal offenses. Heavy fines might be leveled, as a form of punishment, against individuals who use patent pending marks in untruthful and accordingly illegal forms. Terms of imprisonment might also be sought after for a person who uses a patent pending mark without the proper authorization.
Understanding scope of patent pending mark
The right to use a patent pending mark, though it indicates that a patent has been applied for and might be received, at least in the sense of not yet having been rejected, should not be mistaken as any form of assurance that this provision will be granted.