Hi,
Would you know any open source alternatives for some kind of groupware. Would be easy to be able to put up something like:
- Tasks
- Appointments
- Notes
- Whiteboard
- native clients (Windows/Mac/Linux)
There are a couple of projects, but all don't seem really complete. A lot are in Beta, and others just seem to miss some possibilities.
I would like to use this to help coordinate the work in the office, with somebody being a lot away.

openGroupware
Did you have a look on OpenGroupware?
Havn't tried it myself but read about it and it looks not to bad
greetings
Jörg
Open exchange
We have used open exchange for a while here in Harpenden - but we have had too many problems with administering it so we are actually changing to exchange - but we are a big base and I can see how the costs are hugely impractical for YWAM locations!!
Zimbra!
"Zimbra is an open source email, address book, and calendaring server based on open source technologies tied together with a bunch of Java code." - Sitepoint.com
Not exactly everything you asked for but pretty close. There are also some great things from 37signals.com.
"Basecamp is a web-based tool that lets you manage and track projects (or simply ideas) and quickly create client/project extranets."
WorkGroupShare
I use WorkGroupShare from Softalk http://www.softalkltd.com/products/workgroupshare/. It is not a free open source program, but it doesn't take the skill to set up like Exchange Server. You may want to check this out. We are very happy with it.