Teleporter

Teleporters are an incredibly handy way to get around when moving between the swamp, Trade and Temple Quarters. No more spending endless hours trudging from one place to another, this is instant travel. It also economizes on all the fares you'd otherwise be giving the ferryman.

There seems the be a theme in the game about teleporters, perhaps relating to incidents mentionned in the books. Several people, Kalkstein and Leuvaarden in particular, relate stories of unfortunate people who used teleporters less than successfully. These individuals often arriving at their destinations in less than one piece. The actual functionning of the teleporters is not really explored further, but in the cut scenes, Geralt does look like he's being "sucked in" when he uses them.

In Act II, Kalkstein gives Geralt a teleportation crystal which enables him to travel from any place of power to Kalkstein's basement laboratory in the Temple Quarter.

In Act III, Geralt finds 3 teleporters: one in the elven ruins in the Trade Quarter sewers, one in Triss Merigold's bedroom (hers is a magic mirror) and one in the Mage's Tower in the swamp. These greatly facilitate getting around.

Triss' mirror also functions as a telecommunicator (as is shown in the opening cut scene of Act III), very versatile... and I suppose Triss herself, on occasion, could be considered a teleporter. She does teleport our hero at least twice during the game: first to the Salamandra Base and then away from danger. There's a suggestion of a third time, otherwise how would Triss have gotten an unconscious Geralt out of the swamp and into her bedroom in the Trade Quarter anyway?