A very lightweight program with its easy-breezy installation, in a few clicks of the mouse you are ready to start backing up your documents and pictures with 2GB available for free web space.
During the installation process, a folder is created on your computer where you can drag and drop the file(s) you want to back up. These files will be marked for uploading and will be uploaded in some time, depending on your bandwidth and bandwidth settings of the program. This folder is accessible through Finder.
You can share files with your family and friends using this service. You can dedicate one folder to do exactly that. Also, you can access your online space using some smart phone, which can be super helpful for professionals.
The program authenticates your computer with the server, and multiple aliases can be used in this one program, but I am not sure how this works as I have not done so myself. Servers are slower than Dropbox but not that much slower when you consider the additional free space you receive.