[Motel75]

Yes, Heyah comes with 4 Zl, I was off slightly, though my point is the same: SIM cards are cheap. Sorry I wasn't clear about the original post; I mentioned Heyah as an example of the cheapest useful SIM anywhere. I don't know about Malta, though.

As far as Germany goes, I wouldn't bother with a used D2 (ie, Vodafone) SIM on eBay if the seller knows nothing about it. Just get a new one in Germany from somewhere other than an official Vodafone store (which tend to be expensive). Big department stores sometimes have low prices on mobiles including SIM that can be less than a SIM pack at a Vodafone store (such as the aforementioned Sagem, which I got at Quelle).

Old Voda (D2 Privat) prepaid cards sometimes have better rates than the present ones, and 10-second billing, which they have since abolished for prepaid (and those with it had to send an SMS to Vodafone to prevent this from being removed). However, with any Vodafone card, the first change of tariff is free, but all subsequent ones are 5?, so you're better off with a new one. However, new cards usually come with CallYa Basic (39 cents per minute in all networks, 69 cents to other mobiles), which is not such a good value for most people, so you probably will want to change it.

One option for a group or family coming to Germany in the next few weeks is for everyone to buy an smobil card at the local Schlecker store, as the smobil-to-smobil rate is 1 cent (but limited to 200 min per month, and only till September or so).

However, for longer-term users, or those wishing to return every year and a half or so, smobil might be less desirable compared to Aldi Talk, which has lower overall rates (15 cents to all networks and only 5c between Aldi Talk users), and which also allows validity to add up to two years, whereas smobil (and Vodafone Compact, etc) restart it when you recharge (max 6 months or less). Recharges are only available at German Aldi stores, though possibly on eBay as well.

Alternatively, simyo lets you recharge with a credit card, but has no lower simyo-to-simyo rate.

(Since I mention it, restarting the validity with each recharge is also the policy on all Polish cards except for Heyah and Era Tak Tak, which is why I use Heyah: you can add it up to 1 year validity, though the minimum spend per year is 200 Zl, or 50?, more than twice that of normal German prepaids, 20?.)