Add new images to existing nodes I am using imagefield to make photo albums. Now I want to allow all registered users to upload new images to any photo albums and it should get added to the exisiting album. I do not want to give them permission to edit the node. How can I do this?
You'll likely have to change what you mean by "edit the node". You could use Field Permissions to restrict what they're able to change when editing the node.

But to truly accomplish this without letting them "edit the node", you'll need a very complex custom solution that would be unreasonably complicated for an answer on this site.