S scale 1:64 - its the perfect size and delightfully idiosyncratic! Cambrian, light railways, industrial, narrow gauge and American shortlines. Also 1:152 2mm Finescale and 2mmNG, and some overseas modelling in 1:160 N scale.
Thanks for your encouragement guys. Yes Jerry, I have a full schedule of 'drilling and grinding' planned for 2013 ...and beyond! (but Horsetan will be relieved that I've given up the home-dentistry, he he)