“I’m in Germany as a guest and want a cheap mobile data plan for a week”

So you’re an international guest in Germany for a week or a month and you want to use your smart phone, but you don’t want to pay for the usually insane international data roaming charges on your regular mobile plan? If you have a SIM unlocked phone, I’ve got a 10 Euro solution for the week for you – the mobile Internet plan actually only runs E4.95/week, so you’re even getting some extra voice/text for that – and a German phone number.

Steps:

1) Ensure that the phone is actually SIM unlocked. If you don’t know whether your phone is SIM locked, it likely is. Unlocking procedures vary, sometimes you can’t unlock, at all. I’m on T-Mobile USA and they are very good about it. For T-Mobile USA, the process description is here. You can dial the 1-800 number through Skype (or Communicator for the Microsoft folks) for free. If you’re on T-Mobile, they’ll send you an unlock code by email within 24h.

2) Find a Vodafone store. Here’s a list of all stores in Berlin, for instance. Click the first letter of the city you're in in this list to find a store.

3) Get yourself a Vodafone CallYa SIM card. The SIM card will cost 10E, if they’re asking what plan you need, you likely want CallYa 5/15. Here’s the tricky bit: For the registration procedure you’ll need ID (passport) and they’ll ask for a German mailing address. I’m not going suggest anything here, but in case you’re convinced that you don’t have a German mailing address for this week, you might want to think for a moment whether that’s really true.

4) Put the SIM card in your phone. You will need to enter the PIN that comes with the card. There’s a scratch-off field in the leaflet that holds the card; the four-digit number is what you need. If the phone is SIM locked, you will also need the SIM unlock code right then.

5) Unless the folks in the shop help you out right there, call 22044 from your phone “Tarifmanager”. You’ll (hopefully) be asked whether you want German or English menus on the first call (I was). You need to navigate to Options (Press 2), Data (3), then you can select the “CallYa MobileInternet Flat for a Week” (2). Once you select this, you’ll be asked to confirm the selection (1). At this point you’ve got a data subscription for a week. 200MB limit after which they’ll throttle down to GPRS speed. Congratulations.

6) Configure your phone for data. The Access Point Name is “wap.vodafone.de”, the Proxy Server is 139.7.29.1, port 80 (required). For Windows Mobile, you need to create a new connection in your connection settings, set it up as GPRS connection, and configure the access point. Once the connection is created, you can configure the Proxy Server. Here’s a walkthrough; even though it’s in German you should be able to follow that if you know your way around Windows Mobile a bit.

7) Done.