Hi,
In webcallback status page, there should be button to cancel ongoing call. If some body dial some number by mistak or incorrect number then he could stop the initiated call.
After call is finished, there sould be option to add dialed number in web address book if not already there.
How about implementing webcallback as provider? That will be good option for provider like NoNoH.
Telèfon Web: Betamax php script
Instructions - finarea-midlet - Google Code
Regards.
majo