Just wanted to share an online experience.
I came across this website called Geni from a friend of mine. It helps you construct your family tree. For each family member you add to the tree, you have the option to specify his/her email address. Each such user receives an invitation to view and/or modify the tree. You can also add photos/thumbnail pic and personal details (birth/death date/place, occupation, education, etc) for each person on the tree.
It is really interesting when more people related to you get drawn into the excitement and you end up seeing more people in your family tree and eventually you get to know more about your roots and the origins of your family.
That said, Geni doesn’t make your family tree for you. It only provides you with an easy-to-use, fairly secure interface. It’s up to you and those related to you to actually build the tree!
My family “tree” (well, it’s more of a jungle now) is now eight generations deep and covers family members up to two centuries ago. Kind of makes me stop and think of the distant past.