Mozilla has announced Firefox Send, a free encrypted file-sharing service that works in any browser. To share a file, you simply visit the Send site and drag your file to a box on the Web page. Unregistered users may upload up to 1 gigabyte in files, while registered users have a 2.5 GB allowance. After uploading your files, you choose an expiration time for the link used to share them. Expirations can be set for number of downloads — one to five, 50 or 100 — or in increments of time, from five minutes to one hour, one day, or seven days.