I`ve worked with hundreds of salespeople and the difference between those that are mediocre and those that are outstanding usually have only one thing that differentiates them...consistency. Whether it is doing a presentation, cold-calling or anything else related to their selling efforts, top-performing salespeople track what is being done or said so that they know what works and what doesn`t. When they find what works, then they can use it consistently. After working closely with a sales team for only a month I can tell you what works and what doesn`t work because I track every piece of their selling activities, including what they say when cold calling. Every person selling can do the same for themselves. Just write down what you say on each cold call and track the ratio of calls to appointments for 2 weeks. Then, change the wording just slightly, i.e. use the phrase "I want to meet with you to discuss your needs" instead of "asking for an appointment", and then track your results of calls to appointments to see if there is a change.
If a salesperson doesn`t use a script as a map, they are flying blind and hoping that whatever rolls off their toungue will somehow, someway work. I like what Doormat said about the movies. Can you imagine the chaos that would be caused if there were no scripts!
So, yes, use a script as a map. Be conversational. And, remember, the point of the cold call is just to set the appointment, so don`t get caught in the trap of selling over the phone if the appointment was your goal.
Now, if you`re talking about cold-calling and actually making a sales pitch over the phone, then that`s a whole other discussion.