Just don't let the bartender see.
[QUOTE=SirDrDunk;2625679]I've passed girls my digits in the past all you got to do is take the napkin that your drink sitting make sure it's not a wet spot go in the bathroom put the digits on it and come back and while you talking turn with your back to the bartender and hand it to her under the bar works every time.[/QUOTE]Be very discrete. Don't let anyone see you passing numbers. Most girls will just ask for your digits and discretely call you before you leave. Be safe!