Mobile Receptionist is a program for your Windows Mobile 5.0+ phone that can handle incoming call, SMS, and email notifications, and execute actions depending on a set of criteria.

Use cases:
Watching a movie: set up rules to respond to missed calls and text messages with an SMS saying you’re unavailable and will get back to them later.
Archiving: set up rules to forward all text messages to your email account.
Multiple phones: if you have a work phone and a personal phone, after working hours you could set up rules on your work phone to send SMS to your personal phone if the call/message is urgent.
Remote notification: If you’re entering a secure building where you can’t bring your phone, but have internet access, set up rules to send you an email every time you missed a call, got a text message, have an upcoming appointment.