A year ago it was quite a painful operation to get Estonian ID card working with Ubuntu 7.04. Instructions provided by Ideelabor included manual compilation of OpenSC. Yes, it worked, but this is not the best solution and definitely not the fastest one.
Now it is Ubuntu 8.04. You do not have to compile anything any more. Look (but consult Ideelabor instructions for possible updates):
sudo apt-get install opensc pcscd libccid
sudo apt-get install sun-java6-jre sun-java6-plugin sun-java6-fonts
sudo update-java-alternatives -s java-6-sun
sudo zcat /usr/share/doc/libopensc2/examples/opensc.conf.gz \
Now edit `/etc/opensc/opensc.conf`. Set these:
try_emulation_first = yes;
lock_login = false;
reader_drivers = pcsc, ctapi;
All done. Continue with digital signatures.