Matthias put a great article online on how to add some grip to your slippery spot. To cut a long story short: you just have to put some magnesium on it. What works for climbers can work for flatlanders as well. So kids, it´s time to get some magnesium on that lovely new tiled floor in your parents living room!
Update: there are health concerns about that idea. Please check the forum or get a gasmask.