This is a feature of which I'm particularly happy about — drag and drop from desktop to the web app!

This magic is accomplished with the help of a Firefox extension, so at minimum you need the Firefox browser, or, possibly, some other mozilla based browser.

Basically you can drag and drop pictures to the editor, photo album, layout editor, any files to the file browser, file archives and so on - this work almost everywhere where there is the possibility to upload files. No need to use that awkward "browse" feature of the browser anymore, just drag and drop and you are done. Here's a demo.

Install the extension if you have Firefox 1.0 or newer.