DSL and Telephone

DSL
Crocodilian-Rooms in Berlin offers a lot of flats and rooms where DSL is already installed. Unless otherwise mentioned, you have to bring your own notebook in order to use DSL.  
If you decide to get DSL for a flat which has not got it yet, it is no problem ordering it. But this makes only sense if you stay in Berlin for a longer period of time. Please also ask how long it will take until you get - sometimes German phone companies or internet providers are not the most reliable. 
Meanwhile, DSL should be available in any part of Germany - although it could be that there are some parts of Eastern Berlin, where it is not possible yet.    

As an alternative, you can use internet cafes. In all central parts of Berlin, there are internet cafes everywhere,. You only pay between 0,80€- 1,00€.     

Cheapest DSL flatrates
Telephone and DSL packages + all providers 
DSL and telephone calcultor
Availability of DSL

Telephone
If the apartment you rent does not have telephone, you can also get a contract from Deutsche Telekom or any other provider.
If there is a telephone line, you can either pay a telephone deposit to the landlord or -lady or you can do a direct debit with Deutsche Telekom (only possible if you have a German bank account). The disadvantige of paying a deposit is, that the landlord usually gets the telephone bill of the last month after you have already moved out.