  Polymeric methyltrioxorhenium (poly-MTO) represents the first example of an
inherent conducting organometallic oxide. It adopts the structural motives and
transport properties of some classical perovskites in two dimensions. In this
study we present resistivity data down to 30 mK which exhibit a crossover from
a metallic (d$\rho$/d$T >$ 0) to an insulating (d$\rho$/d$T <$ 0) behavior at
about 30 K. Below 30 K an unusual resistivity behavior, similar to that of some
doped cuprate systems, is observed: initially the resistivity increases
approximately as $\rho \sim$ log$(1/T$) before it starts to saturate below 2 K.
Furthermore, a linear positive magnetoresistance is found (up to 7 T).
Temperature dependent magnetization and specific heat measurements in various
magnetic fields indicate that the unusual resistivity behavior may be driven by
spatial localization of the d$^1$ moments at the Re atoms.
