HW-SW interoperability by means of standard distributed object middlewares has been proved to be useful in the design of new and challenging applications for ubiquitous computing and ambient intelligence environments. Wireless sensor networks are considered to be essential for the proper deployment of these applications, but they impose new constraints in the design of the corresponding communication infrastructure: low-cost middleware implementations that can fit into tiny wireless devices are needed. In this paper, a novel approach for the development of pervasive environments based on an ultra low-cost implementation of standard distributed object middlewares (such as CORBA or ICE) is presented. A fully functional prototype supporting full interoperability with ZeroC ICE is described in detail. Available implementations range from the smallest microcontrollers in the market, to the tiniest embedded Java virtual machines, and even a low-end FPGA.