Abstract: A collapsible chair has a sheet of flexible mesh material supported by four arms extending in a tetrahedral pattern from a self-locking, gravity-operated base joint. The outward ends of the front arms are angled upwardly. U-shaped stabilizing legs pivot outwardly from the front arms to a forwardly extended position. The support arms are received in pockets in the flexible sheet to permit detachment thereof. The arms are pivotally connected to the base joint to permit them to be folded parallel to each other. The hollow rectangular lower ends of the arms telescopically receive similiarly shaped guide arms on the base joint to permit axial movement between an upward position in which the arms are freely pivotable and a downward position in which the arms are automatically locked in the tetrahedral position.

Abstract: A waterproof wallet, which is a highly protective receptacle for driver's licenses, credit cards, and cash, is adapted to be attached to a garment of a surfer. A foldable member houses two hermetically sealable inner pockets. Two openings are formed and sealed in the member to provide means of attachment when the member is folded or left open.

Abstract: Six-sided cubic blocks with interfitting and repelling sides have selected representations on each side according to predetermined patterns of relationships between side structures and representations. The blocks are assembled in horizontal and vertical arrays to achieve numerical goals of representations on faces of the arrays. Two persons work on the vertical array from opposite sides seeking to attain their own goals, while preventing opposite persons from attaining their goals.