A convertible item, such as an item of furniture, comprising: a front end and a rear end; a plurality of shelf units, wherein each said shelf unit comprises a substantially horizontally extending leave and at least one leave support for supporting the leave; a drive system operably connected to each said leave support such that the leaves remain substantially horizontal when the shelf units are moved between a substantially vertical shelf configuration whereby the leaves extend in spaced substantially horizontal parallel planes above one another, and a substantially horizontal configuration whereby the leaves are positioned next to one another in a substantially horizontal plane between the front and rear ends; and an anti-tip leg system comprising: a front leg assembly comprising at least an upwardly extending pair of front legs spaced apart from one another, each said front leg comprising a front leg upper region operably connected directly or indirectly to a shelf unit or a part of the drive system, and a front leg lower region supporting at least one wheel, a rear leg assembly comprising at least an upwardly extending pair of rear legs spaced apart from one another, each said rear leg comprising a rear leg upper region operably connected directly or indirectly to a said shelf unit or a part of the drive system, and a rear leg lower region supporting at least one wheel, and a linkage assembly interconnecting the front and rear leg assemblies (30a, 35a), wherein: a spacing between the front and rear leg lower regions increases as the shelf units move towards the substantially horizontal configuration; the spacing between the front and rear leg lower regions decreases as the shelf units move towards the substantially vertical shelf configuration; said front and rear leg lower regions remain in contact with a ground surface at all times; and said linkage assembly determines a maximum spacing allowable between the front and rear legs (31a, 36a). a front end and a rear end; a plurality of shelf units, wherein each said shelf unit comprises a substantially horizontally extending leave and at least one leave support for supporting the leave; a drive system operably connected to each said leave support such that the leaves remain substantially horizontal when the shelf units are moved between a substantially vertical shelf configuration whereby the leaves extend in spaced substantially horizontal parallel planes above one another, and a substantially horizontal configuration whereby the leaves are positioned next to one another in a substantially horizontal plane between the front and rear ends; and an anti-tip leg system comprising: a front leg assembly comprising at least an upwardly extending pair of front legs spaced apart from one another, each said front leg comprising a front leg upper region operably connected directly or indirectly to a shelf unit or a part of the drive system, and a front leg lower region supporting at least one wheel, a rear leg assembly comprising at least an upwardly extending pair of rear legs spaced apart from one another, each said rear leg comprising a rear leg upper region operably connected directly or indirectly to a said shelf unit or a part of the drive system, and a rear leg lower region supporting at least one wheel, and a linkage assembly interconnecting the front and rear leg assemblies (30a, 35a), a front leg assembly comprising at least an upwardly extending pair of front legs spaced apart from one another, each said front leg comprising a front leg upper region operably connected directly or indirectly to a shelf unit or a part of the drive system, and a front leg lower region supporting at least one wheel, a rear leg assembly comprising at least an upwardly extending pair of rear legs spaced apart from one another, each said rear leg comprising a rear leg upper region operably connected directly or indirectly to a said shelf unit or a part of the drive system, and a rear leg lower region supporting at least one wheel, and a linkage assembly interconnecting the front and rear leg assemblies (30a, 35a), wherein: a spacing between the front and rear leg lower regions increases as the shelf units move towards the substantially horizontal configuration; the spacing between the front and rear leg lower regions decreases as the shelf units move towards the substantially vertical shelf configuration; said front and rear leg lower regions remain in contact with a ground surface at all times; and said linkage assembly determines a maximum spacing allowable between the front and rear legs (31a, 36a). a spacing between the front and rear leg lower regions increases as the shelf units move towards the substantially horizontal configuration; the spacing between the front and rear leg lower regions decreases as the shelf units move towards the substantially vertical shelf configuration; said front and rear leg lower regions remain in contact with a ground surface at all times; and said linkage assembly determines a maximum spacing allowable between the front and rear legs (31a, 36a).