I use dropbox everyday.
It is a file system that allows you to share your files with your colleagues.
I have a file that I share with other colleagues in my department. You could use it for all the Algebra teachers at in your department so that they all would have access to the files.
It is also a back up file system.
If anything happens to a file on my computer, it is backed up on the servers at Dropbox.com.
It is also a file system that can be shared with all your own computers. I can download the software so that any computer I own will have the files in my dropbox in them.
I can also login to dropbox.com and access my files from any computer that is connected to the Internet.
Best of all, you get 2 GB free of storage. That is a lot of storage.
Here is a short video that I made showing it's highlights.