Plug-in for the Locale app, which allows you to have a condition for when there is a call in progress.
Requires Android 2.1+ and Locale 1.0+
Note: This plug-in runs a small background service to keep phone state. Please exempt it from any task killers, if you have one.
Version 1.1: Ask if ringing counts as on a call.
In Locale Call Status Plug-In 1.1