Set Availability to Away while on the Phone
 

I was just thinking about some ways to make the N900 more efficient for me and I came up with this idea (it may not be that new). Since the N900 has the availability at the OS level, could that availability be set to "Away" or "On the Phone" when taking a call? Here's the use case:

1. I set my availability to Available on my IMs
2. I receive a phone call and answer it (or make a call)
3. My availability is set to Away with status message of "On the Phone".
4. I end the active phone call
5. My availability is set to it's previous state of Available.

Is this possible?