I first tried #owncloud many months ago, and many things did not work at all, which was frustrating. I guess "something", or rather "many things", was (were) fixed in the last months. I am now able to access my owncloud calendar and contacts from any computer using either Kontact or Thunderbird (with Lightning and SOGo addons), and from my Android phone using Carddav Sync and DAVDroid. File sync works perfectly well too, using either the desktop or the mobile client. Good job owncloud devs!!