Call them Stargates, Jumpgates, Fargates, Hypergates or just an invitation to every unwanted pest from the far reaches of the Galaxy to visit, they're absolutely necessary if we're to have the glorious Science Fiction action we desperately need. Could they actually be built? Modern physics may permit: how to glue black holes together to build a wormhole, how to avoid the dangers of spaghettification, radiation poisoning and paradox noise, and just what would it take to build one in practice.