  Radio observations with Very Long Baseline Interferometry (VLBI) provide the
highest resolution in astronomy. Combining earth-bound with space-based
telescopes and advancing the observations to mm-wavelengths increases the
resolution even further. These methods enable us to probe directly the
vicinities of the presumed central black holes in active galactic nuclei (AGN)
and the powerful jets emanating from these objects. We provide a brief review
of recent results in this exciting research domain and we discuss the
opportunities for future work possible with the advent of new instrumental
developments.
