This question already has an answer here:
When I recieve a call it only shows the name of the contact. Is it possible to shows the number as well?
The same applies when I call a contact, it only shows the name, but I'll watch that thread for options on outgoing mods or apps.
The reason this is important to see is that I have 2-3 numbers for many contacts and it is very important for me to know at a glance if they are calling from work or home or mobile.
My phone is jailbroken, so don't feel tied to the stock iOS if a good solution exists in a jailbroken app or modification to the OS. Clearly a non-jaibreak solution would help the most people, so I'd prefer that if possible.