three versions named S,M,L
basically, calls are @ 25ct, sms @ 19ct.
charging >20€ --> no bonus
charging 20€ --> 5€ bonus
charging 30€ --> 20€ bonus, which equals 1 min airtime @ 15ct, sms @ 12ct, like "alltime"
bonus can be eaten up within 6 months, but is irretrievably lost from then on. (unlike "alltime" where it's good for no more than a month)
whereas chargings are seized n withdrawn after 6 months, but are then again coughed up & topped up as soon as the next charging will be conducted.

release is due nov 30th

edit: bonus' validity can be extended by recharging 20€ and up within 6 months.

And O2 Germany is giving away their prepaid cards including ? 2 of credit for a couple of days. Just go to http://www.cancatch.de/ and click a SIM card.

Unfortunately you'll need a German address to ship to, but since they won't prove it, you can also provide a hotel's or friend's address.

Interesting, but what is the "Pers?nliche Kundenkennzahl"?

Its like a pin access code which the hotline verifies if you call them (or if you want to use certain functions on the online billing platform. You define this when you sign up for the card.

Ok, but it asks it on the site http://www.cancatch.de/ if you try to get your "free" Loop cards... what do I have to put there if I'm not already an O2 customer?

No, it asks you to define your number there which you can use to identify yourself later...