Gmail users can now select multiple attachments and add them simultaneously to an e-mail message. The new system simply opens your operating system's file explorer, and supports selecting of multiple files at once. Best of all, it includes a status bar for each file as it uploads (just like Flickr's Flash uploader does) to let you know how far along each file is. This can be comforting if you're adding a file that's close to Gmail's 20MB attachment limit, since you can see something other than a spinning loading icon. It also warns you if you're over the size limit before the files start moving, which is a nice touch.
One area where desktop e-mail programs still beat Gmail is letting users drag and drop their files, which has been seen to work on other Web storage and upload services using a Java applet.