Today I discovered cb2Bib, a very useful tool for extracting BibTeX data from clipboard contents or PDF papers. It doesn't work perfectly (get real, how could it), but might save a lot of tedious copy and paste if combined with JabRef.
Only hitch during installation: Only src RPM available, rpmbuild complained about not finding qmake/qt4, which is understandable, as I hadn't installed libqt4-devel, which provides it. Afterwards everything worked flawlessly.
# rpmbuild --rebuild cb2bib-1.2.0-1.src.rpm
# rpm -Uhv /usr/src/packages/RPMS/x86_64/cb2bib-1.2.0-1.x86_64.rpm
The resulting GUI is mainly self-explanatory point-and-click.