you might try this:
http://phonetag.com/products.html
it costs but it was all that i could find
Works for:
SimulSays is available for the following phones:
Blackberry Curve Cingular
Blackberry 8800 Cingular
Blackberry 8800 T-Mobile
Blackberry Pearl Cingular
Blackberry Pearl T-Mobile
Windows Mobile Smartphone
*UPDATE*
found another called callwave (cost too)
http://www.callwave.com/landing/mobi...neService.aspx
But in order to get it to work you need to (only for sprint users):
You have to make sure the customer service rep understands that you want "No Answer Call Forwarding (No Reply Forwarding)" not simply "Call Forwarding". No Answer Call Forwarding (No Reply Forwarding) is free the other is not. Also have the rep do it for you, there are three things that need to be changed:
No Answer Call Forwarding (No Reply Forwarding)
Busy Call Forwarding (Busy Call Transfer)
Unreachable Call Forwarding (Phone Off Forwarding)
The rep can do this for over the phone, even if you don't have another phone to call them from. They can do it while you are on with them. But, make sure you have cleared out your Sprint messages first, this will turn off your Sprint mailbox and all of your messages will be lost.
*UPDATE#2**
There is a free version of callwave out there but I can't seem to find it... still looking.
this artical says callwave is free :
http://www.redorbit.com/news/technol...ide/index.html
but I cant find it on their site so maybe they move to subscription service only now????? idk