On every BibSonomy page that lists publications you can get to the export page of the currently displayed publications by hovering over the options icon that you will find on the top right of the list.
In the appearing menu the link labeled "more" takes you to the export page:
After choosing the number of publications you can select the export format from the drop down list above or the links below.
I hope this new feature makes it easier to export publications from BibSonomy.
Happy exporting and tagging!