  Searches for extra spatial dimensions remain among the most popular new
directions in our quest for physics beyond the Standard Model. High-energy
collider experiments of the current decade should be able to find an ultimate
answer to the question of their existence in a variety of models. We review
these models and recent results from the Tevatron on searches for large,
inverse-TeV-size, and Randall-Sundrum extra spatial dimensions. The most
dramatic consequence of low-scale (~1 TeV) quantum gravity is copious
production of mini-black holes at the LHC. We discuss selected topics in the
mini-black-hole phenomenology.
