The rise and rise of USB as a charging standard continues: http://s7g3.scene7.com/is/image/ae235?%24p%24&layer=0&size=281,281&layer=1&size=281,281&src=ae235/18294_P This is neat as it avoids those heavy clumsy bricks. (But I don't know the comparative efficiency of the power conversion.) The X90 bus between London and Oxford now has something similar in the mains sockets. Jonathan