An substantially planar information device is provided comprising: a memory module including a memory device and an electrical interface to connect the memory device to a complementary interface of a computing device; and a housing including a recess in which the memory module can be removably received, a receptacle to receive the electrical interface when the memory module is received in the recess, wherein the memory module and the housing are substantially planar such that the information device can be affixed to a planar substrate without substantially changing the profile of the planar substrate.