Well I have been playing with Cocos2d iPhone development API for the last few weeks and have found it very easy to use.
Have an animated sprite on the screen responding to touches with a background tile map moving with the player sprite.
Here is the link to cocos2d iPhone – http://www.cocos2d-iphone.org/
I am also using Lightwave 3D for the game art – http://www.newtek.com/lightwave/
I am using Tiled for my tile Map – this is the Mac OSX download version – http://www.mapeditor.org/ and there is a Java version that you can download at well that currently has more features than the Mac OSX version – http://sourceforge.net/projects/tiled/files/
Andreas Löw who developed TexturePacker is sending me a copy of this package and i will let you know how I go creating a Sprite Altas (spritesheet) with this package – http://texturepacker.com/
The other choose for creating Sprite Atlas’ that I have found is Zwoptex. There is a Mac OSX download version here – http://zwoptexapp.com/ and a Flash version here – http://zwoptexapp.com/flashversion
Here are a few more interesting Cocos2d sites: