Whiteclaws "Draw" as in holding left click to create a series of tiles/objects.
Anyway, lots of people have asked about more layout editor features, tiles, etc. but it seems there are no immediate plans to add anything of the sort. The "solution" here is to use tiled background objects. Alternatively you can go all out and build your own editor, or use Tiled with RexRainbow's .tmx importer.