If you are looking for an easy way to switch between multiple spell check dictionaries in the Pidgin IM application, have a look at the the Purple Plugin Pack. This plugin pack includes a plugin called Switch Spell which enables you to do just that. To install this on Fedora distro

yum install purple-plugin_pack-pidgin

Now all you need to do is enable Switch Spell in the plugin manager.

(Note: In order for this to work you need to install multiple Aspell dictionaries)