Zeolites are one of the most important classes of catalysts as is apparent from their wide use in oil refining, petrochemical processes and fine chemicals manufacture. The micropores (typically 0.5-1.0 nm) of zeolites are extremely well defined, i.e. by the crystal structure of the alumino-silicate. The confinement of the active sites, being it acidic or redox, by the intracrystalline micropores is important for such phenomena as shape selectivity and high activity. By the same token the small pores give rise to slow mass transfer of reactants and products that may cause low activities, secondary reactions and even coking. In order to maintain the beneficial effects of the micropores and enhance mass transfer, several approaches have been followed (Cat. Rev. 45 (2003) 297-319). Here we discuss the options to generated mesopores in zeolite crystals thus creating highways through the crystal that lead to shorter path length for the molecules in the micropores. Steaming and acid or base leaching is shown to be  a versatile tool, although new characterization approaches (3D-TEM, thermoporometry) have proven that cavities in zeolite crystals may be formed while cylindrical pores are preferred. We will also discuss a new method to generate mesopores by using secondary templates (e.g carbon nanofibers) for the mesopore network during zeolite synthesis.