Recently I travelled to Berlin for a technology conference. Strangely I don't have a data plan for my "smart phone" at home in Canada, but when travelling there is nothing that makes getting around a new city easier than having a smart phone with a data plan. I don't know how I did it before smart phones. I guess I just got lost a lot.
I did some research on how to get a data plan while in Germany, but nothing really came up that was all that recent. So I thought I'd detail how I found an inexpensive data plan.
Have an unlocked phone. Buy a BlauWorld SIM card at the Alexanderplatz Saturn store. Go back to your hotel and use your hotel wifi to register the SIM card using your hotel's address in the Blau online activation form. Once the form is completed, wait about 30 minutes, then put the SIM into your phone, enter the SIM card's pin number from the letter in your BlauWorld package into the phone when requested. Done! Now you can access the internet via your phone.
After doing a bit of research I decided (rightly I believe) that a Blau card would be easiest, mostly because they have an English version of their website. Specifically I was looking for a BlauWorld card, which is apparently a card often used by foreign workers in Germany. Further, it doesn't seem to have much in the way of restrictions--just a simple online signup. Also, in theory they are widely available, though I have only seen them at Saturn stores.
Saturn is a technology store--they sell TVs, computers, cell phones, and, of course, BlauWorld SIM cards. The first Saturn I tried did not have a BlauWorld SIM card package, but they suggested I to go to another location--the Saturn at Alexanderplatz. So I did, and they had a BlauWorld card for about 10 euros, which is quite low-cost. It comes with a SIM card and a 10 euro credit. With the credit the BlauWorld SIM card is essentially free.
The BlauWorld SIM card can be resized to nano, micro, and regular SIM card sizes so it should fit in all phones.
There is an English version of the Blau website which is quite helpful if, like myself, you can't read German. Click on the Activate tab and follow the instructions. You'll need the phone number from the letter in the BlauWorld package to start the activation. Enter your name and a German address. I used my hotel's address. It might take a couple tries to get the right information into the right fields.
During the activation I was able to select a 1GB data plan with the 10 euro credit that came with the SIM card. Actually the 1GB option was the only option during the initial activation. There are other options you can pick once you've registered the card completely if you want SMS and/or voice, but it would cost extra. The SMS and voice plans were fairly expensive, but not unreasonable. I didn't need voice or SMS. Data was just fine.
Once the registration is finished, wait 30 minutes or so then put the SIM card into your phone and start it up. Enter the pin number from the letter.
At this point you have 1GB of data, which is perfect for a weeks stay, and it only cost 10 euros total, for both the SIM card and the 1GB plan.
Now, knowing you can use your phones map application, you can venture out and explore Germany.