BirdieSync

For sync a mobile under win5-6:
http://doc.ubuntu-fr.org/tutoriel/sync_wm5-6
It's written in French.
Pleeeeeeeeeeeeeease make a version for Ubuntu

An other link :
http://forum.parallels.com/thread2743.html
to use Activesync with parallels

As it was mentioned previously, the problem is that the technology used on Mac is different from ActiveSync and is based on iSync. So it would very likely need a lot of work to do this adaptation... I have found this making activesync job on Mac: http://www.markspace.com/missingsync_windowsmobile ...