Editors

Are you looking for a texture atlas editor ? or for a new TileMapAtlas editor ?
Here are some projects done by the cocos2d community:

Texture Atlas Creator (http://robertjpayne.com/textureatlascreator/)
Features:

• A simple Texture Atlas editor. Useful if you are going to use AtlasSprites!
  
• It lets you import individual images
  
• You can place these images withing the atlas
• You can save the texture atlas image
• It export the coordinates into an .xml file
• It's a web application

Tiled + .tga plugin, a cocos2d TileMapEditor (http://kwigbo.com/wp/2009/03/15/cocos2d-alternative-map-editor/)
Features:

• It is a plugin of Tiled, a popular tile editor.
• The plugin supports 3 layers: tile, code and bkgr
• The plugin supports 2 tilesets: tiles and code
  
• It lets you export the map to a .tga file (the format supported by TileMapAtlas)
• A very good alternative to the PGU level editor