If you have pidgin installed in ubuntu,install Skype API plugin is a good choice so that you can have your Skype contacts displayed with Pidgin.
To install skype API plugin,first download .deb package by running this command:
wget http://eion.robbmob.com/skype4pidgin.deb
Then install it by type:
sudo dpkg -i skype4pidgin.deb
Or,you can download libskype.so file to /usr/lib/purple-2/ or ~/.purple/plugins.
Type one of the commands to download libskype.so,then copy it to /usr/lib/purple-2/ or ~/.purple/plugins.
wget http://eion.robbmob.com/libskype.so(for i386)
wget http://eion.robbmob.com/libskype64.so(for amd64)
Now restart you pidgin,click on Add account and you will see Skype on the options.