What is the best way to do this?

[MisSFiT]

Asking a girl for her number is good and all, but I think it's really annoying when you aren't interested anymore, say after a date, and they keep calling you. That's why I always get the number, that way if I want to call I will.
It all comes down to the simple point that if someone is interested they just are, if they aren't then there really isn't anything you can do get past that friends part. Real life isn't like the movies.

And no, I don't think Dr. Phil is a role model or even a great relationship expert, I was just naming a name to name a name...
You know what I mean?