GLaDOS from Portal on your GPS? That incredibly unique voice you hear as you play through The Orange Box is that of Ellen McLain. She first appeared in Half-Life 2 as the fantastic voice of the Overwatch – the authoritarian government. Her voice also pops up during Team Fortress 2 as an announcer. But her voice very much makes a starring role as GLaDOS, the computer program in Portal, one of the most engaging and creative characters ever to appear in a video game. This voice can now be added for free to you Tomtom GPS via Tomtom Home application or by installing the files manually. Here is a short video of snippets of this awesome voice in a short navigation around London. (WARNING: this is evil – you need to be a little geeky and have a fair amount of patience to really appreciate this on your sat nav!).