Flow Chart Software?

Do you folks know of any good programs to create flow charts based on pre-determined questions and answers?

For example, like a cold call phone sales pitch where its obvious the caller is reading from a script.

Im trying to put together something 'visual' for Ryan when it comes to traffic flow, etc and i think having something with a flow chart would be the best way of getting this information across to him.

So, any reccomendations for software to do this type of thing please?

Regards,

Lee

I'd be interested in checking something like this out also, if for nothing else to learn. I'll let someone else do the googling though :)

I use Microsoft Visio, not sure if you've already explored that or not...