Count missed calls as a condition
When I'm at work, Locale sets my phone to silent. If it's in my pocket and I don't notice the vibration, it's no big deal, because I'm at work. But what if someone really needs to get in contact with me? After the fifth missed call with my phone in my pocket, I would really prefer Locale to swap "Silent" for "10% ringer volume". After the sixth, 20%, and so on.
It could also be used to crossover with the Gchat and Auto-sms plugins - After n missed calls, put up a status on google chat "Sorry to whoever's trying to contact me, I don't have my phone nearby." Or, as a battery saving measure, rather than letting someone drain your phone battery by ringing it over and over while you can't get to it, have the phone set itself to airplane mode IF battery < x AND missed calls > n.
All the settings are already in Locale - I just hope for the condition