Google's Cash for Gold Offer
Google has announced that if you send the company your patent, they may offer to buy it. It is pretty obvious what Google is doing. They are looking for patents that could be asserted against them, and hoping to buy them up for pennies on the dollar.
If you send your patent to Google, and it makes you an offer, decline the offer and immediately contact a technology licensing firm - like General Patent - to find out what the patent is really worth.