The initial phone call should be very well scripted, with the primary goal being to get the clients contact information, but also some idea if they are your (type of) customer with a project that is appropriate for your company. If you have a script you can also keep the conversation short and to the point. The ultimate goal is for you to decide if you are going to try to set an appointment with this client, if you are going to try to prequalify the client by discussing fees up front, or deciding that this is not your (type of) customer and thank them for the call. Just because someone calls you or wants a "free estimate", does not mean that you are obligated to meet with them. Even in recessionary times you want to be able to properly screen a customer on the phone to determine if it is a good fit. If it is, than do every thing you can to service the client, if not than move on. Time wasted on a bad customer, even an initial meeting, is time you are taking away from good customers.
If a client is "crazy"

in the beginning of the process, you can guarantee that you will be crazy by the end of it

.