Dropbox is a program which allows you to share files between various computing devices - even smart phones - via Dropbox's online storage. This also makes sharing files with others easy, but there are plenty of security options to ensure that only those you want to have access will be allowed.

Up to 2GB is free, with subscription options ranging up to 100GB. Bandwidth control options are also available, so that your entire network connection isn't hogged by the application.