I second the Dungeon Tile group on Yahoo. I use their sets and Pymapper, a DT program, to plan my encounters, then I take poster tack ("Monkey Snot," Scrib) and affix them to black poster board (22"x30"). If I need a larger area, I use multiple poster boards. This has really sped up use of Dungeon Tiles, since I no longer need to pull them out of a bag and set them up during play.