Plugin to circle items in a photograph?

Plugin to circle items in a photograph?

I'm trying to build a web app which allows users to tag items in a photograph.  The items are seldom rectangular, so plugins like imgAreaSelect aren't quite right.  I'd prefer something that feels like smoothly dragging your finger around the items on an ipad, rather than a "click on points of a polygon" like polyclip.js.  

I want to be able to show the tags when the user mouses over the "circled" area, so I need to be able to save the select path in some form.

Any suggestions?

Thanks!

Chris