  A concise review of observations of the $\alpha$ dynamo effect in laboratory
plasmas is given. Unlike many astrophysical systems, the laboratory pinch
plasmas are driven magnetically. When the system is overdriven, the resultant
instabilities cause magnetic and flow fields to fluctuate, and their
correlation induces electromotive forces along the mean magnetic field. This
$\alpha$-effect drives mean parallel electric current, which, in turn, modifies
the initial background mean magnetic structure towards the stable regime. This
drive-and-relax cycle, or the so-called self-organization process, happens in
magnetized plasmas in a time scale much shorter than resistive diffusion time,
thus it is a fast and unquenched dynamo process. The observed $\alpha$-effect
redistributes magnetic helicity (a measure of twistedness and knottedness of
magnetic field lines) but conserves its total value. It can be shown that fast
and unquenched dynamos are natural consequences of a driven system where
fluctuations are statistically either not stationary in time or not homogeneous
in space, or both. Implications to astrophysical phenomena will be discussed.
