Wow. I did something similar a while ago, and it bombed. There was a girl at my bank who I got to know a little bit, had a few short conversations with, and she always smiled at me when we talked, etc. All good signs. One day she said 'hi' to me and we spoke very briefly, and she went off to take a phone call and I finished my business. I wrote down on a slip of paper 'Samantha's home phone number is _______' while I was getting my money, and then handed it to while she was on the phone. She wrote down 'call me here (430)493-4032' -- in other words, call my direct line at the bank. Now, that would all be great, except the next few times I saw her, she wasn't as friendly as she had been. Not necessarily rude, but definitely uncomfortable, no smile, very little eye contact, and alot of uneasiness. So in my eyes she went from a happy, friendly girl to a somber, unfriendly girl overnight -- not really the kind of girl I'd want to spend time with, in any case.
There are a few big problems with this (and similar) approaches, but the biggest is that it's weak -- it doesn't come from a position of strength. I might as well have written down "Would the banking goddess please grant me my wish to humbly obtain her home phone number so that I, the unworthy peasant, may phone her with my message of worship" (which is a line that would do Louis & Copeland proud).
Not one of my finer moments.
-Brian