Joe Walker shows a tip from DWR.Next:

I asked Joe to show us something interesting that he is playing with on DWR and he quickly obliged by showing us a new file upload and download feature that allows you to do new fancy things with files.

What is cool about this is that the APIs from Java and JavaScript lands feel right in each, but to do this DWR has to do a lot of fancy work to hide the details.

This is some crazy coolness

(Via Ajaxian Blog.)