Efreit's DC Domain: Offers custom tiles and maps.
Opan's Custom DC Tiles: Offers a tropical island tileset for download.
Terra Incognita: A guide to Dungeon Crafter as well as tiles, maps and backgrounds for download.
The Dungeon Crafter Challenge: Offers downloads of winners of past challenges, an idea box and rules of the challenge.
Wingnut's Custom DC Pages: Offers custom tiles, maps, and backgrounds.