To give you some background without giving too much away, I've had my e-mail hosted on an Exchange 2010 server since around April. I also take advantage of Office Communications Server 2007 R2 quite a bit. I consider my OCS phone number my primary number. I also have a local office phone number and work cell phone. All in all, that's 3 voicemail "boxes" to keep track of.
Most of the time, I'm out of the office, but I still want people that call the office to reach me as long as I have cell signal. Many times while inside buildings or datacenters, cell signal is poor or you aren't allowed to bring your cell phone inside. Usually, if I don't have cell signal, I'll have some kind of Internet data connection, so this is a great example of using OCS for reach-ability while at a customer site. Of course, this assumes you have permission to connect into their network.
Where am I going with this? Unified Communications/Messaging. I know you probably hear that buzz word quite a bit, but this is a good example.
I forward my office phone to my OCS phone number.
I forward my work phone number to my OCS phone number, if there is no answer on the cell phone.
Why do I go through all this effort to get missed calls to my OCS number?
This:
I did edit this message to say "name" instead of the actual name of the person called. Ditto for the phone number involved.
If the person that left the voicemail spoke clearly and wasn't in a noisy environment, Exchange 2010 generates a decent text transcription. Many times, I don't have to listen to the actual voice message.
End result: I avoid having to remember 3 different set of voice mail PINs. I avoid having to remember to check the office voice mail system. If I am in a meeting and can't take a call, I can read the voicemail message inside Outlook without ducking out to check voicemail on my cell phone.
Please be aware that most cellular providers will charge you minutes for forwarded calls, which is the reason I have it setup to only forward the call if there is no answer or the phone line is busy.
As of 06/02/09, the phone codes to do this on the Verizon network are:
Conditional forwarding (only on "no answer" of cell phone):
*71 plus 10 digit phone number
*73 cancels
Unconditional forwarding (all calls forwarded):
*72 plus ten digit phone number
*73 cancels
Busy transfer:
*90 plus ten digit phone number
*900 cancels
As an example, if I wanted to conditionally forward my calls to
616-555-1234, I would enter in
*716165551234 into my cell phone and hit [Send].
If you are not on a "home" Verizon tower/network, these codes will most likely not work. Not all phone numbers seem to work, and I do believe you need to have the 'Call Forwarding' option as part of your cell phone plan.
I am sure many other providers have the same type of functionality, but Verizon is the only provider that has a tower near my house.

Thanks go out to Britt Baubie for the Verizon information.
Determining the Scalability of Combined Client Access and Hub Transport Server Roles in Exchange 2007
Tracked: Jun 05, 13:07