Gmail sending attachments trick: multiple simultaneous files
It's not all that amazing, but, as they haven't given a lot of hype to this, if you haven't directly read Google related news, you might be still using Gmail the old way without knowing this simple trick: you can attach multiple Gmail files at the same time, simultaneously.
Of course you could send several attached files at the same time. But you had to attach each file individually in the older version. So you had to select the files to attach one by one, in different file selection windows. Now we can add more files to attach in the same file attachment selection window, just by holding the CTRL key while clicking the additional files.
And now they have included an attachment sending progress bar as well.