The use of ultra short laser pulses delivered by powerful laser systems has permitted the emergence of new approaches for generating energetic particle beams. By focusing these laser pulses onto matter, extremely large electric fields can be generated, reaching the TV/m level well in excess than those produced by conventional accelerators. As a result, the distance over which particles extracted from the target can be accelerated to hundreds of MeV is reduced to distances on the order of millimetres. These laser-produced electron beams have a number of interesting properties and could lead themselves to applications in many fields, including medicine (radiotherapy), radiobiology (short-time-scale, low dose irradiation), chemistry (radiolysis), non-destructive material inspection by radiography, and accelerator physics.