I've been looking for a way to exchange files with friends and family for a long time. I used WWWFileshare which is terrific but is reliant on your ip address. If you have a dynamic ip like mine it changes occasionally. This makes WWW kind of awkward.
I recently discovered Foldershare. It is very unique and the ideal setup for family and friends. It can be as private as you like with you in total control of what you share, how you share, and who you share with. FS encrypts downloads/uploads making the file sharing experience safe and secure - probably a tool business would find interesting as well. 2 people that have the software installed can upload, download, update, or alter the libraries depending upon permissions. Only one person owns the files and has total control and delegates what others can do. For people who not have the program all they need to do is open an account with Foldershare to be able to download files from a friend. They can only download. Of course, you are limited to what bandwidth and hard drive space is available to you. I found the program to work nicely.
http://www.foldershare.com/