Berlin rent-a-bike

I took a short holiday and went to Berlin last weekend. And I noticed these bikes standing there, then today I followed my daily blog reading routine and found out about them via psfk. It's an interesting concept where you phone the number printed on the bike with a code that's also printed on the bike and after giving your credit card details. You'll be given a special code to unlock the bike. Type it in and go of into Berlin. Costs are 7 cents per minute or 15 Euros a day.

The only problem I think it has is that I've seen them around but never in a pair, so two tourist traveling together couldn't rent such a bike.