Ubuntu Firefox + Thunderbird integration
Just switched to my Kubuntu 7.10 laptop for mobile working.. found that KDE has a bug which means it does not pass on the mailto: clicks via the Default Applications option in System Settings.
Workaround is to create a Firefox user.js with this code in it:
user_pref("network.protocol-handler.external.mailto", "true");
user_pref("network.protocol-handler.app.mailto", "/usr/bin/thunderbird");
This gets it working, although I wish KDE functionality would keep working between releases!