I am currently developing a relatively simple 2D, topdown oriented adventure game for the iPhone and was wondering what would be the easiest way to create the maps for my game. I figured I would need some kind of visual editor that would give me immediate feedback and would allow me to place all objects in the world exactly where I want them. I could then load the saved representation of the world I create in the editor in my game.

So, I am looking for a simple map editor that allows me to do this. All the objects in my game are simply textured rectangles build up from two triangles. All I need to be able to do is position different rectangles/objects in the map, and give them a texture. I am using texture atlases, so it would be useful to be able to assign portions of textures to the objects. I then need to be able to extract all the objects from the saved representation of my maps, together with the name/identifier of the texture(atlas) they use, and the area of the texture atlas.

I have looked at some tile-based map editors like Tiled and Ogmo, but they don't seem to be able to do what I want. Any suggestions?

EDIT: a more concrete example: something like the GameMaker level editor, but then with added export functionality in a handy format.