This is what happened:
http://www.puaforum.co.uk/field-repo...hone-fail.html
To be fair, it was quite funny. But it was also unacceptable, a point I made forcefully to my flatmate when she revealed that she does it all the time.
In response to your second question, I don't really think about it. It's not a big deal. It's like telling a mate to come over and watch the football later.
"Tell you what, let's hang out later this week. Plop your digits in there and I'll ring you, let you know when I'm free"
I made it up now. It's not a structure except in the sense that it is a normal, structured sentence. Think of it as like ordering a pint. I'm sure that most of the time, you use the exact same way to order it but you don't think of it as a "routine" or "structure", you just do it. The best thing I can probably tell you is, if you want a girl's number, there's no wrong way to do it. Tell her what you want, and if she's not up for it, it's her loss.