How do you keep your online address-book?

[Timothy Murphy]

What do people recommend for keeping a list of contacts
on the computer?
I presently use OpenLDAP, but I'm not completely happy with it.

I think my main requirements are:

1. It must be held on one computer, and be accessible from others.
2. There should be a simple GUI program to add contacts.
3. It should be possible to add contacts to and from mobile phones.
4. It should be reasonably compatible with KMail and other KDE applications.
5. It should be reasonably compatible with Windows XP.
6. It should be flexible, allowing additional fields to be added later.

I'm interested to know what the most popular method
of keeping an address-book online under Fedora.

-- 
Timothy Murphy  
e-mail: gayleard /at/ eircom.net
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland