I'm looking for a plugin will allow users to create their own postcard online, with some modifications of course. I need to let users upload images, add text on top of those images, and then save the resulting creation as an image file or PDF for printing. Any tips?
Sounds like you want something with fabric.js
Although I am not sure exactly how to save with that script. I know there are ways to save as images with whatever you put on the canvas. Like this: http://motyar.blogspot.com/2010/04/save-html5-canvas-data-as-image.html
This looks like a pretty article on saving as well: http://www.nihilogic.dk/labs/canvas2image/