Together with one of my clients, I have been testing a software (and service) that does online backup, file sync, file sharing, and version control. Very easy to use: you designate a folder to store the data that should be updated; start creating files in it; and share specific folders with other people if you want to synchronize files with them. Free, up to 2 GB (there are monthly fees for larger data volumes). So far it works fine, but I have only been testing it since yesterday.
DropBox, from
www.dropbox.com. Read the license; one thing you have to be aware of is in a free account, data may be erased after 90 days of inactivity.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)