Plugin: Simple insert of images into custom fields?

I posted this onto the end of another thread so i’m sorry if you’ve read the question already:

Are there any plugins in existance that allow file upload and insertion of the image url into the value field of a custom field? or something similar for conveniently adding images to custom fields. Integrated upload function would be great, but isnt essential; a way to browse pre-uploaded images and insert their urls into the custom fields on selection would do the job too.

I know there are simple workarounds, but im looking for a way to provide my (non technical) clients with a foolproof way of adding images to custom fields.. for page design reasons i’d prefer images to be added to custom fields rather than being embedded in the post body.

Thanks for your time!