The combination of microscopy and femtosecond laser illumination turns out to be very attractive and useful for imaging in engineering, physics and biomedicine. The high laser intensity and low average power allow for the generation of nonlinear imaging signals that contain information complementary to classical imaging modes. The Current state-of-the-art is reviewed and nonlinear current imaging and imaging of ballistic electron transport in Au-films is discussed in detail. (C) 2002 Elsevier Science B.V. All rights reserved.