How many times have you hit the email send button, only to realize seconds later that you forgot to attach an important file to the message? I’ve done it too many times to count. One of the interns on the Gmail team has come up with a feature that automatically detects if you have mentioned an attachment in the message, but not attached it. A friendly warning asks if you mistakenly forgot the attachment. That is a feature that should have been in every single mail program written since attachments first became available!