I ran into a site I thought was great.
So good I made it a Google referral at www.iarelative.com
Upper right of the page.
You can build a family tree on line.
After playing with it for a couple hours I can see a potential.........
Take a family tree branch you don't know much about.
e.g. My Aunt's son
Start the tree.
Invite other family members to add to it.
Add the information to your database and update the site.
The site accepts GEDCOM export so you don't even need to type.
A hang up is that each export you do overwrites the site with current
information you send.
You need to sync the database at the site with your database before you
Seems like an idea waiting to happen.
Keep in mind that FREE sites tend to disappear on the internet so you do
need to make sure you keep a local copy available to you.
It's All Relative