Need server software to share calendar & contacts

[hampshire]

Hopefully someone can help me out with this, I want to be able to share my contacts and calendar with my wife. We both have Windows Mobile devices and use those exclusively for contact, events and email (no syncing with Outlook on a PC). We used Mail2Web for a while but it never worked all that well and now each have our own address book and calendar on our phones.

So what I am looking for is something I can set up with a shared server account (linux) that will allow us to sync our contact and calendar back and forth between both our phones and the server and that has a web interface where we can view/edit our calendar/contacts/emails. I would prefer it to have some sort of push for email, contacts and calendar as well but this is not a deal breaker.

Does anyone have any suggestions on something free and open source that will meet my needs, it is a shared server so PHP/MySQL would probably be the easiest path but I am open to any suggestions. I have already tried egroupware but did not like it, it had far more than I think I needed and had a few problems.

So in summary
shared calendar
shared contacts
email
shared to do list would be nice as well

Thank you.