If you bring your own bottle of wine into a restaurant, chances are you'll be charged a corkage fee, which usually ranges from $5 to $30 depending on the attitude of the establishment. The fee is used to pay for the waiter's service and for the use of the glassware; it's also a means of discouraging patrons from bringing their own wine (since most restaurants sell their wines at double the retail price). It's considered bad form to bring a bottle that's already on the menu (makes you look cheap), so be sure to call ahead and confirm that the wine you plan to bring isn't already on the wine list.