position markers on image and save

Hi

I'm a newbe to javascript and jquery but not to programming-
Thanks for any help:)

I'm looking to build a user form where the user can
drag and drop markers onto an image and then
retrieve/send the resulting new image with markers back to the server
for processing.

Any Ideas what UI functions / Plugins will be in the right direction to achieve this?

Anyone familiar with some existing similar functionality?

Thanks very much!

Paul