Show all packages not available via subscribed channels or repositories i.e show packages installed via other repos:

# yum list extras
Sample output:

Loading "installonlyn" pluginLoading "security" pluginSetting up repositoriesReading repository metadata in from local filesExtra PackagesDenyHosts.noarch 2.6-python2.4 installedVMwareTools.i386 6532-44356 installedjohn.i386 1.7.0.2-3.el5.rf...