Hi
The service is available to Corporates on MTN. It is live. Its basically a Walkie Talkie feature (Handset Dependant) that works over the GPRS network. So basically as long as you have MTN signal, you are in range. All the users at your firm will be provisioned and will be in contact with each other. Its bills per "push". Meaning that each time the button is pressed and something is said, it counts as a charge. Normally with the contract options for Corporates, each user is given a bundle of pushes to use e.g. 50/100/500 per month. Out bundle charges will apply per price plan.
Hope this helps, If you need further information let me know.
Regards
DD