We present an investigation of current cross correlators in mesoscopic conductors. Making an analogy to the optical Hanbury Brown Twiss experiment we discuss how quantum statistical effects and two-particle interference effects can be investigated with current cross correlations. We also discuss how current cross correlations can be used for detecting two-particle entanglement and to perform quantum state tomography, a complete reconstruction of the density matrix of the quantum state emitted from a mesoscopic conductor.