Abstract: A rigid trailer hitch is disclosed that uses pressure produced by a wedge into force against trailer hitch receiver walls, while still retaining a retaining pin as a backup. The wedge can be driven by rotary force translated through a compound miter or a split wedge across a retaining pin.

Abstract: A novel method at least includes: receiving at least one placement offer for the placement of an advertisement, the offer including proposed consideration; accepting an placement order; and displaying an advertisement which is the subject of an accepted placement order on a plurality of mobile, changeable advertising message displays carried by a plurality of coordinated automobiles, which changeable displays are capable of displaying more than one separate message at different times. Each changeable message display at least includes: a visual display; a multiple advertising message generator coupled to the visual display, the multiple message generator adapted to generate a plurality of different messages; and an message selector adapted to select a current message to be displayed.

Abstract: A novel advertising method at least includes: receiving at least one advertising placement offer for the placement of an advertisement, the offer including proposed consideration; accepting an advertising placement order; and displaying an advertisement which is the subject of an accepted advertising placement order on a plurality of mobile, changeable advertising message displays carried by a plurality of coordinated automobiles, which changeable displays are capable of displaying more than one separate advertising message at different times. Each changeable advertising message display at least includes: a visual display; a multiple advertising message generator coupled to the visual display, the multiple advertising message generator adapted to generate a plurality of different advertising messages; and an advertising message selector adapted to select a current advertising message to be displayed.