Puttgarden [1] is Germany's gate to Scandinavia. There is a car/train ferry port with ferries to Rødby in Denmark. Usually there are long Hitchhikers can get over for free because drivers only pay for their vehicle. If you are searching for a lift you should tell people about this possibility - otherwise they might not take you with them just because they think it's too complicated or they'll have to pay. You can probably easily find a ride to Copenhagen or Sweden.