Many libraries in Germany use Resource Discovery Services (RDS) for inventory management. BibSonomy provides a direct RDS interface and is supported by mostly all university libraries in Hessen (HeBIS-Verbund).
Here is a list with the libraries that certainly support BibSonomy:
You may ask your library to find out if BibSonomy is supported. The following instructions describe how you can store publications from the library catalogue directly in your bibliography in BibSonomy.