Facebook's hit all sorts of growth records in the last month or so, with its private stock reaching an all-time high ($65 per share) and its user count topping the 500 million mark. Now, it looks like the organization may expand in another way, as a rumor has it ready to acquire Hot Potato. Hot Potato is a check-in service that takes possibilities other than physical locations into account. Users can, for example, say they're listening to a particular song or reading a certain novel, not just check in at a concert or a bookstore.