  We calculate the distribution of current fluctuations in two simple exclusion
models. Although these models are classical, we recover even for small systems
such as a simple or a double barrier, the same distibution of current as given
by traditionnal formalisms for quantum mesoscopic conductors. Due to their
simplicity, the full counting statistics in exclusion models can be reduced to
the calculation of the largest eigenvalue of a matrix, the size of which is the
number of internal configurations of the system. As examples, we derive the
shot noise power and higher order statistics of current fluctuations (skewness,
full counting statistics, ....) of various conductors, including multiple
barriers, diffusive islands between tunnel barriers and diffusive media. A
special attention is dedicated to the third cumulant, which experimental
measurability has been demonstrated lately.
