Intense ultrashort lasers have been a driving force for numerous basic science problems and applications in the last 10 years. The intensity of these laser pulses allows exploration of highly nonlinear phenomena during the interaction with matter. The propagation itself of these pulses is not a trivial issue: self-induced nonlinear effects lead to unexpected propagation behavior. Filamentation is the field () that addresses this unexpected propagation modes, its properties and applications. We will discuss different facets of this field and the research conducted at IESL-FORTH with a special accent on filamentation tailoring, using for instance virtual photonic lattices, or non-diffracting wavepackets in the form of Bessel or Airy beams. A recent demonstration of Airy light bullets will be discussed as well. In the second part of the talk we shall discuss the evolutions related to ultrashort secondary sources with emphasis on terahertz (THz) sources. Our advances towards the generation of table-top intense THz sources and the control of its properties will be presented, as well as applications in spectroscopy and nonlinear THz optics – a field in its birth.