Yes. To do this, just go to the Request Backups link under Backups and select the projects you would like to back up. It's just a nominal fee of $2.50 per backup per project. If you'd like regular backups, you can go to the Manage Subscriptions link under Backup links and set up a scheduled backup for as little as $5/month per unlimited projects. You can create as many backups as you'd like, and download them from the My Backups screen. Backups are retained for 30 days. Please note that Free accounts are not currently able to take advantage of this feature.