German Cell Carrier Advice (iPhone, AT&T)

German cell phone contracts run for a minimum of two years, so you can't purchase a plan for only one month. You best option would be for a pay-as-you-go option. You'll chew up minutes very quickly in Austria and the Czech Republic, particularly if you're browsing the internet or sending pictures.

PS- Only one day for Munich and you're coming from Baden-Baden? Let me make an alternative suggestion that saves you time and saves you from going far out of your way to visit ho-hum Baden-Baden. If you're looking for a spa treatment, get it at Bad Neuenahr (near the Mittelrhein), Wiesbaden or Therme Erding outside of Munich. Any one of these would be more convenient to your trip. If you have no interest in the baths, Baden-Baden simply isn't interesting enough to justify a visit unless you're driving by anyway.

I wish there was an easy answer to this question. Actually there should be one. However, all prepaid cards only come as regular sized SIM-cards, some also come as micro-SIM. However, none come with a nano-SIM. You always have to order it - it's free, but it takes a week or two.

So forget about your iPhone 5C. But there is hope for your 4S.

What model are your iPads?

Any pre-paid SIM card in Germany requires a registration process. You'll have to register against a real physical address (which of course can be the street address of your hotel). It can take up to 24 hours for a SIM to be ready for use. Also then you'll have to "book" your data flat - that might take another 6 hours. It's not very comfortable.

There is a decent alternative though: http://www.hotspot.de, Deutsche Telekom (T-Mobile)'s really good national WiFi service. It's available on almost all ICE trains but also across towns and cities. The monthly flat rate for this (and you can use more than one device with it, just not simultaneously) is €29.95. You pay for it online with your credit card or PayPal upon your first usage.

'You'll have to read the fine print about using the Vodafone sim outside of Germany, I know it's possible in some countries BUT at a very much higher rate.'' I can verify that Vodafone works in at least Austria, Switzerland, Belgium, the Netherlands, Finland, Denmark, Sweden and Norway. But yes, you pay a much higher tariff.

If you're only planning on making a few calls and using limited data, you could also consider using the AT&T international roaming plans. That would be the easiest solution.

If you do use the AT&T international plan you will keep your phone number as is and can accept incoming calls in case of an emergency. You can also add the international texting for about $10 for 50 outgoing texts... incoming are free. I have done this on a number of trips as I need to keep things simple. Same phone, same number... however I do not really need to make calls within Europe. Data is off, unless on Wifi.

I bought a T-mobile cellular data-only plan for my ipad air last month. I bought it at the T-mobile store in the central shopping district in Frankfurt, the Zeil. The nano-sim card cost about 10 euros. It included a 10 euro credit for data. A month of data, 500mb, cost 15 euro. I had 10 euro credit, but had to pay 15 euro more because they said that was the minimum they could accept, so I guess I still have 10 euro credit. I was satisfied with the coverage and speed. You can probably get a weeks service and stay within the 10 euro credit. The advantage of using a T-mobile store is you get their help. If you buy a sim in a grocery store, then you're on your own.

I also bought a month pass for wifi using T-mobile hotspots. I used this a lot more that the cell service, since there was no data limits. The coverage was very good in the larger towns and on the ICE trains. Coverage in smaller towns, not so good. They also offer day and week plans. There is an ios app for this.

Thanks, all.

Thank you for the great replies !!

Tom - I'm working on a Black Forrest alternative ... there are honestly so many good choices!

My T Mobil plan is $50 per month, and international data and emails are unlimited. Voice is $.20 per minute--cheapest around.

You can start and stop the plan month by month--no 2 year agreements.

And an AT&T GSM phone unlocked will work on T Mobile. (Verison's phones are incompatible.)

That's the best deal going.