How can I change a field's widget type on its node edit page? I have a node type that uses Fuploader image field widget. When a user creates new a node of this type, I want them to be able to use the fuploader widget to upload images. When the user edits that node at some point, I want to switch to the normal imagefield widget. How can I accomplish this?
Login in as super admin: 

content management ->content types -> edit [your content type]->managefields

click on configure of that field and there you will see second button which named "Change basic Information"

Click on this button and will get the way to edit widget type.