For some time now, I have been using owncloud to sync my personal files. It is a lot like a personal dropbox.
Why do I use owncloud ? It is a great way to seamlessly synchronize file across machines. In this respect, it works a lot like dropbox. It has a client which works with linux, os X (mac) and windows. Initially is seems one can sync 50 GB, though I suspect this is a limit is by Andrew. All of the info stays on Duke servers so there are no privacy issues.
I have not explored the file sharing possibilities much. They exist, but seem not as advanced as dropbox. For two people in the department, they work a lot like Dropbox. There is a shared directory which both people can interact seamlessly. If one person is not in the department, the sharing options are mainly web based. You can share files or directories secured by a password to anyone with a web accessible link. You can’t seem to seamlessly share a directory with someone else outside the department as one can do in dropbox. For collaborations such as writing papers of code I personally use Git. It has much better version control than Dropbox or owncloud and it is free (again hosted in the Duke Mathematics department).
There is a web interface at https://cloud.math.duke.edu/owncloud/ . From there one can create links to share a file with someone or retrieve a file when you only have web browser access.
There is also an ipad/iphone client which costs a few dollars. I use it regularly to save file from my phone to my work account. There is also a webdev address
https://cloud.math.duke.edu/owncloud/remote.php/webdav/
which is useful for some other ipad/iphone clients.
To get started, type
% owncloud
at a linux command prompt on a department machine. It should step you through the needed steps. It will create a directory called “owncloud” in your home directory. Any file in this part of your directory tree will be synchronized.