Manipulation of stage elements

Question

I need a library that help me to create an image editor in Adobe Flex, anybody know about someone??? or what do you suggest to me??

I have a site where people can create your own backgrounds for their desktops, they select the background, they can write something over the backgorund, upload their images and put into the stage, something like that, not so complex, but I need that the users can resize and drag to specific location in the stage the images and the textboxes, change colors of the letters and finally they can save their image, anybody know some library that I can use to create this application??

Thanks for the help