Use Dropbox and on a free account? You can probably use an extra 1GB of storage on the service, then. TheNextWeb discovered that if you download the Mailbox iOS app (a company recently acquired by Dropbox), set it up, and then associate it with your Dropbox account, you'll get that extra space. Even if you've already set up Mailbox with Dropbox, you can unlink and relink the services today and get the free 1GB. It works--I just tested it and the whole process took less than five minutes. According to TNW, that extra 1GB sends the total amount of storage you can accrue with a free Dropbox account to 21GB, with referrals and other promotions.